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Author: Russell Stafford

Hortiholic and plant evangelist, Russell Stafford, transplanted his first perennial at age 7 and thereby began a lifelong plant addiction. He is the founder and custodian of Odyssey Bulbs (and Odyssey Perennials), an online nursery specializing in cool and uncommon plants. Russell also works as a horticultural consultant, freelance writer (Horticulture and The American Gardener magazines), and garden editor. He formerly served as Curator and Head of Horticulture at Fernwood Botanic Garden in Niles, Michigan and as the Horticultural Program Coordinator at the Center for Plant Conservation, then located at the Arnold Arboretum in Jamaica Plain, Massachusetts. His academic degrees include a masters in forest science from Harvard University.

Well-Mannered Groundcovers for Shade

Foamflower is a highly desirable native flowering groundcover for shade.

Back when one-size-fits-all gardening was a thing, ground covers for shade were seemingly as easy as one-two-three: creeping myrtle (Vinca minor), English ivy (Hedera helix), and Japanese spurge (Pachysandra terminalis). That is before they all began invading wildlands. All were neatly arrayed under an equally ubiquitous Norway maple or Bradford pear– both equally invasive and troublesome.

It was bound to happen. Introduce lots of one vigorous, spreading plant species, and you increase the likelihood that it will become a pest itself by invading local native plant communities. It did not take long for all three non-native, go-to ground covers to be added to the invasives lists of many U.S. states, particularly in the Southeast and Northwest.

Unfortunately, going ubiquitous presented additional problems in the garden. As anyone who has ever tried to maintain the “perfect” lawn and garden can attest, mass plantings are easy pickings for mass invasions of pests and diseases. Japanese spurge loses a lot of its allure when it’s riddled with Volutella blight, as is all too common these days.

Well-Mannered Groundcovers for Shade

Fortunately, excellent (and arguably superior) ground cover alternatives abound, many of them native. Feeding the soil with quality compost, such as Fafard Premium Garden Compost Blend, at planting time will encourage good establishment from the start.

Twilight Aster

Twilight aster blooms for a long period in summer and fall.

Who says ground covers have to hug the ground? Some situations call for something taller. Twilight Aster (Aster x herveyi ‘Twilight’ (aka Eurybia x herveyi)) spreads by rhizomes into large swards of broad-leaved rosettes that give rise in summer to leafy 2-foot-tall stems. Plants are crowned with clusters of pale lavender flowers for many weeks in late summer and fall. An incredibly adaptable thing, ‘Twilight’ can handle situations from dry shade to damp sun. This eastern U.S. native goes dormant in winter.

Sedges

Many native sedges are evergreen and make lush groundcovers for shade.

Botanically speaking, they’re not grasses, but sedges provide much the same look for shade with their clumps of narrow-bladed leaves. Masses of low sedges such as Carex pensylvanica and Carex rosea (both eastern U.S. natives) make excellent low-foot-traffic lawn substitutes. For a bolder look, try a clump of seersucker sedge (Carex plantaginea), whose strappy puckered evergreen leaves contrast effectively with lacier shade subjects such as ferns.

Green-and-Gold

Green-and-gold is semi-evergreen and bears loads of bright golden blooms in spring that attract native bees.

Green-and-gold (Chrysogonum virginianum) is a hardy, attractive woodland native. “Green” references the dense spreading rosettes of fuzzy, crinkled, heart-shaped leaves that hold their color and substance through much of winter. The “gold” is provided by the numerous little yellow “daisies” that spangle the plants in spring and repeat sporadically until fall. Native to woodlands in the Southeast U.S., Chrysogonum virginianum is hardy well north of that, to Zone 5.

Robin’s Plantain

This is one of those rare plants you can plug into the garden just about anywhere – sun or shade.

Often occurring as a rather doughty lawn weed, this plantain (Erigeron pulchellus) is a nearly evergreen eastern U.S. native that occasionally assumes much more pulchritudinous forms. The cultivar ‘Lynnhaven Carpet’, for example, grows into handsome carpets of broad fuzzy gray-green leaves that are decorated in spring with pink daisies on 18-inch stems. It’s one of those rare plants you can plug into the garden just about anywhere – sun or shade. Another delightful selection of robin’s plantain is ‘Meadow Muffin’, with contorted leaves that give its rosettes a bit of a cow-pie look.

Allegheny Spurge

Allegheny spurge has leaves that are elegantly splashed with silver mottling, lending the plant a distinguished look totally lacking in Pachysandra terminalis. (Photo by Zen Sutherland)

Although not a rapid runner like the aforementioned Japanese spurge, our Southeast native Allegheny spurge (Pachysandra procumbens) far outdistances it as a desirable ornamental. The whorled evergreen leaves – arrayed in mounded 6-inch-tall clumps – are elegantly splashed with silver mottling, lending the plant a distinguished look totally lacking in Pachysandra terminalis. Things get even splashier in spring when conical clusters of frilly white flowers push from the ground, along with the fresh-green new leaves, as the previous year’s foliage fades. It’s one of those early-season garden scenes that makes your heart leap up. Allegheny spurge thrives in moist humus-rich soil, so give it a dose of Fafard compost if your soil is overly sandy or heavy.

Ragwort

Golden flowers light up this native naturalizer in late spring.

Golden ragwort (Packera aurea) and its near look-alike roundleaf ragwort (Packera obovata) provide quick cover for more informal garden areas. Low swaths of bright green rounded leaves emerge from their rapidly spreading roots in early spring, followed a few weeks later by heads of small yellow “daisies” on 2-foot stems. Use golden ragwort in moist garden situations, and roundleaf ragwort in moist to dry niches. They’re both native to much of central and eastern North America.

Creeping Phlox

This evergreen woodland creeping phlox (Phlox stolonifera) from eastern North America will expand into a ground-hugging carpet.

Don’t let its rather dainty appearance deceive you: this evergreen woodland creeping phlox (Phlox stolonifera) from eastern North America will expand into a ground-hugging carpet of small spoon-shaped leaves. It also provides a spring garden highlight when it opens its clusters of proportionately large round-lobed flowers, poised on 6-inch stems. Blue-, pink-, violet-, and white-flowered selections are available, but probably the best for ground cover is the vigorous cultivar ‘Sherwood Purple’.

Whorled Stonecrop

A native sedum that thrives in shade? Yes!

If you think stonecrops are drought-loving sun plants, you’re probably not acquainted with Sedum ternatum. Hailing from moist partly shaded habitats over much of central and eastern North America, it makes an excellent small-scale ground cover in similar garden conditions, although it also succeeds in sunnier, drier sites. Its dense low hummocks of fleshy ear-shaped leaves are studded with sprays of white flowers in spring. This highly effective shade plant is still rather rare in gardens – perhaps because of its family associations.

Foamflower

Frothy 6-inch spikes of white flowers appear in spring above spreading expanses of handsome maple-shaped basal leaves. These features of foamflower (Tiarella cordifolia), combined with a tough constitution, make for one of the best and most popular native ground covers for easter U.S. gardens. Its variety collina is a clumper rather than a runner, so it’s a better choice where a less rambunctious ground covering plant is required.

Barren Strawberry

Semi-evergreen leaves and bright golden spring flowers make this handsome bee plant a real winner in the garden.

Dense swaths of strawberry-like leaves expand steadily and tenaciously to provide attractive semi-evergreen ground cover in most any garden niche, from dry shade to full sun. Saucer-shaped yellow flowers dot the plants in spring, with a few repeat blooms later on. Recently moved to the genus Geum, barren strawberry (Waldsteinia fragarioides aka Geum fragarioides) is one of the best native ground covers for eastern U.S. gardens – under whatever name.

Persimmons and Paw Paws: Fall Fruits of the Forest

So you want to plant a fruit tree? Something that will fill that blank space in the back yard while supplying your family (and impressing your neighbors) with a bumper crop of juicy, scrumptious munchies? Great idea! Of course, you could always opt for a perfunctory apple or peach (which could all too easily develop into a horticultural and aesthetic nightmare). On the other hand, you could plant a tree (or two) that’s native to the eastern United States, offers year-round beauty, and yields succulent fruits that look and taste as if they came from the tropics.

American Persimmons

American persimmons
American persimmons are bitter until after the first frost when they quickly turn sweet.

Case in point: your backyard (if it’s not too small) could grow real persimmons, produced by the only hardy species in the ebony family. How cool is that! Native from the deep Southeast to southernmost New England, American persimmon (Diospyros virginiana, USDA Hardiness Zones 4-9) is a comely, medium-sized tree characterized by knobbly, deeply grooved, “alligator” bark, large oval leaves, and relatively sparse, often sinuous branches.

American persimmon tree bark
The American persimmon is a large tree with alligator-like bark that looks great in winter.

Of greatest interest to culinary gardeners, however, are its flavorful fruits, which put on a show as they ripen orange in late summer and early fall. A heavily fruiting tree gives the impression of being hung with hosts of miniature pumpkins. Astringent at first, the pulpy flesh sweetens and mellows to an eggnog-like flavor as the fruits mature, reaching their peak as they wrinkle and soften. It makes for good fresh eating, as well as for yummy puddings, pies, and preserves. Far less remarkable are the fragrant, pale greenish-yellow, late-spring flowers, which tend to be exclusively male or female, requiring two trees for pollination and fruiting. Self-fruitful persimmons do occur, though, including ‘Meador’, an exceptionally cold-hardy, prolifically fruiting selection that bears at a relatively young age (typically 10 years).

Paw Paws

Paw Paws

If you’d like a cool tropicalesque native fruit tree in a somewhat smaller size, there’s always the only hardy member of the custard apple family. Paw paw (Asimina triloba, zones 5-9) occurs in the understory of rich woodlands from the mid-Atlantic to the Southeast to the Midwest, typically growing as a gaunt shrub distinguished only by its bold, oblong leaves that broaden toward their tips. But it undergoes a total personality change in sunny or lightly shaded gardens, developing into a small, densely leaved, round-headed tree that brings an equatorial vibe to the temperate landscape. It also produces its large potato-shaped fruits much more willingly in cultivation than in the wild, provided more than one variety is grown.

Paw Paws flowers

The fruit’s relatively thin, pale green to yellow-green rind encloses a fleshy interior that turns yellow as it ripens to a custardy texture in late summer or early fall. Flavor varies from delectable to astringent, with the flesh of most named varieties (such as ‘Susquehanna’ and ‘Sunflower’) possessing a delightful, fruity taste reminiscent of banana, pineapple, or mango. Large, bean-shaped seeds also occupy much of the interior but are typically smaller and fewer in cultivated varieties. Curious, fleshy, purple flowers precede the fruits in spring, adding to paw paw’s singular charm.

Inside Paw Paws
Paw paws, also called custard apples, have sweet yellowish flesh with a custardy, banana-like flavor.

Of brief shelf life (and thus rarely appearing in markets), paw paw fruits are best eaten fresh off the tree, or incorporated into puddings, pies, preserves, custards, and ice cream. The flesh freezes well, making for a mid-winter, fridge-to-table treat. In addition to their delectable flavor, pawpaws also abound in nutrients including vitamin C, magnesium, iron, copper, manganese, potassium, amino acids, riboflavin, niacin, calcium, phosphorus, and zinc. As with American persimmon, pawpaw is a tree — and fruit — of distinction, that will do your yard and table proud.

Planting Persimmons and Paw Paws

Paw Paws in sunlight
Paw paws grow well in a little less sunlight and have large, bold leaves that tend to turn yellow in fall.

Get your new tree off to a good start by planting it in spring or late summer in a hole that’s the same depth but several times wider than its root ball. Backfill with native soil, and mulch with a good compost, such as Fafard Premium Organic Compost, topped by 2 to 3 inches of leaf mold or bark mulch. American persimmon grows well in most soils, but paw paw requires a relatively moist, humus-rich soil for optimal performance. Bon appetit! (Click here to read more about how to site and plant trees.)

What Perennials and Shrubs To Plant in Fall

Summer perennials and potted shrubs are great to plant in fall!

“Perennials (both woody and herbaceous) are shifting energy from their tops to their roots, preparing for their fall underground growth spurt.” -Russell Stafford

Gardeners tend to do the bulk of their planting and planning in spring when the horticultural hormones are running high. For many plants and purposes, however, fall is the perfect time to get down to some serious gardening. The best time, in fact.

Fall Growing Conditions

Fall growing conditions tend to be cool and moist–just perfect for new plantings.

Consider the conditions in fall. Soil and air temperatures are typically moderate, beneficial underground microflora are active, and soils retain moisture longer (thanks to the cooler air and lengthening nights). Plants, too, are undergoing favorable changes. Perennials (both woody and herbaceous) are shifting energy from their tops to their roots, preparing for their fall underground growth spurt. Deciduous plants are shedding their leaves, removing their main source of water loss and drought stress. On all fronts, things are geared for root growth, for as long as soil temperatures remain conducive (above around 40 degrees F).

Plant a hardy tree, shrub, or herbaceous perennial now, and its roots will proliferate (as conditions allow) until spring, gathering energy and preparing for a prosperous new year. Compared to an equivalent plant installed next spring, it will have a far more extensive root system, already adapted to the conditions on (and in) the ground. It will grow faster, tolerate drought better, and in almost every other way out-perform its spring-planted kin.

Bulbs for Fall

Hardy spring bulbs must be planted in fall. (Image by Jessie Keith)

Bulbs (including the rhizomes, corms, etc. that go under this term) are a special case. Most hardy spring-blooming bulbs absolutely require at least a couple of months in chilly, moist soil to stimulate rooting and develop and extend their flower buds. These are the bulbs for fall planting–crocus, daffodils, tulips, and hyacinths are among them. Don’t worry about planting them late, especially if you find bags of bulbs on sale in late October. Bulb planting into late November is just fine as long as you can work the soil. Adding a quality bulb fertilizer at planting time will help them flourish.

On the other hand, some bulbs spend winter in a rootless quiescent state and take well to winter dry-storage and spring planting. Many of the latter are frost-tender things such as dahlias, but the winter-dormant group also includes some hardy “bulbs” such as roscoeas and crocosmias.

Plants You Should Plant in Spring

Balled and burlapped shrubs and small trees should be planted in the spring, not fall.

As with all things horticultural, a few provisos apply. Most of the above advantages are nullified in the case of bare-root or balled and burlapped (B&B) plants, which lose many of their roots during harvesting. With their reduced underground resources, they may lack the capacity to replace water lost from stems and leaves during cold windy weather. Fall-planted bare-root and B&B evergreens are especially prone to winter damage. Severely root-bound container-grown plants do relatively poorly with fall planting, for the same reasons. In contrast, container-grown plants have relatively extensive root systems, buffering them against winter weather.

Fall perennials, like Japanese anemones, prefer springtime planting. (Image by Jessie Keith)

Additionally, some plants that hit their prime in summer and autumn tend to languish if planted in fall, whatever the condition of their roots. Many warm-season grasses and fall-blooming perennials, for example, prefer spring planting. Marginally cold-hardy plants may also benefit from spring planting, which gives them more time to establish before heading into their first winter. Small perennials and shrubs in little pots may also need the headstart of spring planting to grow and set ample roots by fall.

Fall Planting Tips

Make sure that potted plants do not have any congested or girdled roots as this will limit fall root growth.

Planting at least 6 weeks before your last frost date will give perennials and shrubs plenty of time to set new roots (click here to determine your last frost date). Whatever you plant this fall, be sure to provide the conditions for optimal rooting. Dig a planting hole as deep and several times as wide as the root ball. If the soil is excessively heavy or sandy, dig an even wider hole, and generously amend the backfill with Fafard® Premium Topsoil. Tease the surface of the root ball to loosen any congested or girdling roots. After planting and watering your new prize, apply a layer of compost topped with two or three inches of a porous mulch such as oak leaves, pine needles, or shredded bark. This will blanket the roots from drought and cold, extending their season of growth. Come spring, you’ll have a well-rooted plant, ready for takeoff.

*Fall is also an ideal time to divide and plant summer perennials! (Click here to learn more about perennial division.)

Native Hellstrip Gardens

The Highline in New York City is filled with some of the toughest natives for urban hellstrips, such as purple leadplant, native grasses, and coneflowers.

Where there’s a sidewalk, there’s often also a hellstrip – that narrow planting space between the walk and the street. Flanked by baking pavement and blessed with soil composed of compacted sand, construction rubble, and the like, it’s not the most welcoming place for plant life. It also confronts unique challenges such as marauding dogs (and humans), traffic visibility restrictions, and road salt. If a plant is over 4 feet tall or can’t handle even a bit of foot traffic or salt spray, it’s probably not suited for hellstrip duty.

Hellstrips take a beating from heat, pedestrians, and traffic. The fuller your initial planting, the better. (This one looks like it will be under foot in no time.)

As it turns out, quite a few plants native to eastern and central North America are more than up to these challenges. After all, environmental conditions in coastal sand dunes, dry prairies, rocky slopes, and numerous other native habitats can get every bit as hostile as those in your typical hellstrip.

To give your hellstrip border a strong overall visual structure, dot it with shrubs and large perennials planted singly or in small groups. Then fill in the gaps with smaller plants, including generous groupings of ground-covering perennials. In future years, edit seedlings and offshoots as desired.

Native Plants for Hellstrips

Butterflyweed (Asclepias tuberosa)

Butterflyweed feeds monarchs and other butterflies and will withstand hellstrip conditions.

Monarch butterflies in your neighborhood will flit with joy if you stud your strip with clumps of this tap-rooted, 2-foot-tall perennial. Native to dry sunny meadows and prairies of Central and East North America, butterflyweed (Zones 3-9) will take as much sun and drought as nature throws at it, answering with an early summer display of orange-red to yellow flowerheads. You’ll likely have even more of it next year, thanks to self-sown seedlings. Lots of other drought-tolerant Asclepias are well worth seeking out and growing – especially the spectacular purple milkweed (Asclepias purpurascens, Zones 4-9). It does indeed produce rich rose-purple domes on stems that are taller than those of butterfly weed (to 3 feet or slightly more). As an ornamental, it’s far superior to its vaguely similar cousin common milkweed (Asclepias syriaca), which has duller flowers and a much more invasive habit (and is best avoided unless you want your border to be ONLY common milkweed).

Twilight aster (Eurybia × herveyi ‘Twilight’); heath aster (Symphyotrichum ericoides)

Heath aster provides good green cover in summer and lovely white fall flowers.

A hybrid of large-leaved aster (Eurybia macrophylla) and showy wood aster (Eurybia spectabilis), ‘Twilight’ (Zones 3-4) spreads relatively rapidly into ground-covering foot-tall swards clothed with narrowly heart-shaped leaves. Thirty-inch stems decked with pale lavender flowers arise in summer, with bloom continuing from early August into fall. A first-great ground cover for drought-prone partially shaded borders, it also does well in full sun. Speaking of asters, prostrate forms of heath aster (Zones 3-9) and its kin can hardly be bettered as ground covers for hot sunny hellstrips. With their needle-like foliage, they do indeed resemble a heath or heather, until their clouds of small daisy flowers open in late summer. The carpeting, white-flowered cultivar ‘Snow Flurry’ is indispensable for covering ground or cascading down a wall.

Coneflowers (Echinacea and Rudbeckia)

Rudbeckia triloba with swarms of relatively dainty burgundy-and-yellow “black-eyed Susans” in summer.

Purple coneflower (Echinacea purpurea, Zones 4-8) and showy coneflower (Rudbeckia speciosa, Zones 3-9) are a bit too salt-sensitive for many hellstrips. Instead, you might want to opt for Tennessee coneflower (Echinacea tennesseensis, Zones 4-9), a somewhat smaller, more graceful, more salt-tolerant take on purple coneflower, with narrow leaves and blunter, horizontal (rather than drooping) petals. The flowers are the usual echinacean purple, in late spring and summer. Its hybrid ‘Pixie Meadowbrite’ is a wonderful little thing with shocks of narrow leaves which give rise to relatively large rose-pink flowers on 20-inch stems. As for rudbeckias, among the best and most adaptable is ‘Prairie Glow’, a cultivar of Rudbeckia triloba with swarms of relatively dainty burgundy-and-yellow “black-eyed Susans” in summer. At 40 inches tall it’s close to being a stretch for a hellstrip planting, but its height is countered by the airy see-through texture of its inflorescences. The somewhat short-lived plants inevitably self-sow.

Robin’s plantain (Erigeron pulchellus)

Can a native lawn weed also be an unsurpassably useful groundcover?

Can a native lawn weed also be an unsurpassably useful groundcover? In the case of the cultivar ‘Lynnhaven Carpet’ (Zone 3-9), the answer is an emphatic “yes”. Large handsome rosettes of broad, fuzzy, gray-green leaves pop up here and there, eventually merging into a weed-smothering mass. It’s adorned in spring with numerous pink daisy flowers on 18-inch stems. Even better, ‘Lynnhaven Carpet’ thrives in just about any soil or sun exposure. Less vigorous but cuter is the Robin’s plantain variety ‘Meadow Muffin’, with congested rosettes of crinkly leaves.

White spurge (Euphorbia corollata)

Dainty white spurge will obligingly seed itself into whatever open patches of soil may occur. (Image by Cody Hough, college student, and photographer in the Michigan area.)

A delightful prairie and meadow dweller that’s ideal for naturalizing among carpeters such as heath asters, white spurge (Zones 3-9) carries flurries of flowers in late spring and summer that give the impression of a tall baby’s breath (Gypsophila paniculata). It’s a much less fussy critter than any gypsophila, however – provided it has ample sun and elbow room for its sparsely branched, 3-foot-tall stems. It will obligingly seed itself into whatever open patches of soil may occur. Numerous pollinators including the rare Karner’s Blue butterfly adore its flowers, and you’ll also love the vibrant orange and red color of its fall foliage.

Gaura (Oenothera lindheimeri)

Gaura is a tireless, heat-loving spring-to-fall bloomer

This tireless, heat-loving spring-to-fall bloomer was profiled a few months back in our piece on perennials that don’t quit. As with many of the other perennials portrayed here, it will seed itself around in any sunny border, giving you plenty of editing opportunities. White-flowered cultivars such as ‘Whirling Butterflies’ are beautiful things, their waving wands of fluttery white flowers making a pleasing complement to echinaceas and other members of the daisy family. You might also want to mix in a pink-flowered variety (look for ‘Siskyou Pink’ and ‘Crimson Butterflies’).

Little bluestem (Schizachyrium scoparium)

Hot sun and sandy poor soil are no problem for little bluestem. (Image by Proven Winners)

We dismiss some highly ornamental and useful plants simply because they’re familiar to us as roadside “weeds”. Such is the case with little bluestem (Zones 3-9), which you’ll see ornamenting hot sunny roadsides across most of the U.S. Yet it has many notable charms, especially in late summer and fall, when its tall plumes of purplish-tan seedheads and its sunset-toned fall foliage put on a show. Several cultivars (e.g., ‘Blue Heaven’ and ‘The Blues’) also stand out in summer with their steely silvery-gray leaves. Another to seek out is the tidy, upright, blue-green Prairie Winds® ‘Blue Paradise’. Hot sun and sandy poor soil are no problem – in fact, they’re its preferred habitat.

Seaside goldenrod (Solidago sempervirens)

Seaside plants such as this goldenrod also grow well on hellstrips.

A plant that naturally grows on sunny seaside dunes and cliffs is ready-made for hellstrip conditions. The mounds of blue-green, tongue-shaped leaves are quietly handsome, and the late summer to fall, 3-foot fountains of sunny flowers are a delight. They’re also a pollinator’s dream (the bumblers, in particular, love them). As with many hellstrip candidates, it actually does and looks best in dry poor soil. It would rather you not pamper it.

Leadplant (Amorpha canescens)

Small shrubs, such as leadplant (Zones 3-8), also have a place in hellstrip plantings. The common name of this 2- to 3-foot shrublet refers to its tolerance of metal-laced soil – and it’s similarly disposed toward road salt. A pulchritudinous prairie native that would flatter any garden, it features ferny pinnate gray-green leaves adorned in early summer with feathery spires of purple-blue flowers.

Chokeberry (Aronia melanocarpa)

White spring flowers, edible fruits, and fine fall foliage are some of the benefits of chokecherries.

Offering showy white flowers in late spring, edible black fruits in midsummer, and gleaming rich green foliage that goes fiery in fall, compact varieties of this widespread native Aronia (Zones 3-9) are excellent shrubby choices for sunny to partly shaded hellstrips (did we mention that it’s also remarkably adaptable?). Selections include 3- to 4-foot ‘Iroquois’ and the even smaller ‘Low Scape Mound’ (which tops out at 2 feet).

New Jersey tea (Ceanothus americanus)

New Jersey Tea feeds pollinators and performs very well in hellstrips.

Here’s another splendid small shrub native to sunny arid habitats in the central and eastern U.S. Its 3-foot stems are covered with frothy white flowers in late spring and early summer, as well as with pollinating butterflies and bees. New Jersey tea (Zones 3-9) also tolerates moist soils.

Planting A Hellstrip

This hellstrip garden in Portland, Oregon. (Mike Darcy)

Late summer and early fall are a great time to plan and plant your own native hellstrip border. So why not get to it? If the soil is extremely compacted, sandy, or otherwise plant-habitat-challenged, you might want to fork in a couple of inches of Fafard Premium Natural & Organic Compost or apply it to the surface after planting. Even if you don’t, you’ll find that most of the plants portrayed here will manage to get by in all but the most extreme circumstances. You may sometimes find yourself wondering whether they’re native to the moon, rather than to the North American region of this planet. These babies are tough.

The Patriotic Perennial Garden: Planting in Red, White, and Blue

Native perennials in red, white, and blue!

What could be more American than a planting of native perennials that flowers red-white-and-blue in summer? If you have a sunny to lightly shaded garden spot with reasonably decent soil, you could celebrate next Independence Day with your own floral fireworks, courtesy of the following perennials. All are native to eastern North America, and hardy to USDA Zone 5. If your soil is excessively sandy or heavy, be sure to dig in a couple inches of Fafard® Premium Natural & Organic Compost before installing your patriotic planting.

Red Garden Flowers

Bee balm (Monarda didyma hybrids)

‘Jacob Cline’ monarda has big bright red flowers that hummingbirds cannot resist.

Few plants are more all-American than the species and hybrids in the genus Monarda, which is endemic to the New World. The frilly, fragrant flower heads of these tall, often vigorously spreading perennials expand in late spring and early summer, drawing in whatever hummingbirds are in the vicinity. Powdery mildew can be a problem in humid, droughty weather, so look for varieties that have been selected for mildew resistance. These include cultivars in shades of brilliant red (‘Gardenview Scarlet’, ‘Jacob Cline’), rich purple-red (‘Judith’s Fancy Fuchsia’, ‘Raspberry Wine’), violet-purple (‘Purple Rooster’, ‘On Parade’), lavender-purple (Monarda fistulosa ‘Claire Grace’, ‘Dark Ponticum’), and hot pink (‘Coral Reef’). All of the above are in the 3- to 4-foot-tall range. Several recently introduced, lower-growing bee balms are also available, including purple ‘Grand Marshall’ (2 feet tall) and bright pink ‘Grand Parade’ (15 inches).

Winecups (Callirhoe involucrata)

Winecups thrive in summer heat.

Another purely North American genus, Callirhoe encompasses 9 species of sun-loving perennials and annuals, most blessed with showy burgundy-red flowers that continue through much of summer. The trailing habit of Callirhoe involucrata is typical of most winecups. If you’re looking for a sun- and heat-loving perennial that will cover ground, cascade down walls, or weave through neighboring plants, you can hardly do better. Fringed poppy mallow (Callirhoe digitata) is more upstanding in habit, to 2 feet tall; it’s also well worth growing.

White Garden Flowers

American ipecac (Gillenia stipulata)

Gillenia is an easy perennial that deserves to be in every garden.

A long-lived, 3-foot-tall perennial with lacy leaves, starry early summer flowers, brilliant fall color, and a tough, drought-tolerant constitution, the eastern North American native American ipecac (and its close cousin, Gillenia trifoliata) is one of the best garden perennials, period. It takes a couple years to get going, which makes it a hard sell in an era when many gardeners and nurseries want instant results. But if you get a chance to buy one (or more), grab it. You’ll thank yourself for years to come.

Other White-Flowered Native Perennials

White coneflowers are bright and beautiful!

Quite a few other U.S. native perennials sometimes dress in white, even if it’s not their typical flower color. Purple coneflower (Echinacea purpurea) sometimes goes albino, as in cultivars ‘White Swan’ and the dwarf, 20-inch-tall ‘PowWow White’. Their large-coned, many-rayed blossoms debut in early summer and continue for many weeks. False dragonhead (Physostegia virginiana) is another purple all-summer bloomer that often diverges into white forms. Cultivars such as ‘Alba’ and ‘Summer Snow’ have the same general habit as purple forms, bearing their flower spikes on 3-foot tall, rapidly spreading plants. Less rampant forms include ‘Miss Manners’, a 2-foot-tall clump-former, and the 15-inch ‘Crystal Peak White’. Purple-to-white also happens in the genus Phlox. Most border phlox (Phlox paniculata) come into bloom after the Fourth. Several other species and hybrids, however, start flowering in June and continue through summer. Look for ‘Solar Flare’, ‘Daughter of Pearl’, and ‘Aurora’, all bearing white, pink-eyed flowers on 2- to 3-foot, mildew resistant plants in spring and early summer with repeat flushes until frost.

Blue Garden Flowers

Anise hyssop (Agastache foeniculum)

Bees love these fragrant blue flowers.

If you love masses of lavender-blue flowers and bumblebees, you’ll want to work this eastern North American native into your plantings, patriotic and otherwise. The flowers are carried from late spring through much of summer on airy spikes undergirded by clumps of coarse toothed oval leaves. All parts of this large, 3- to 4-foot tall, short-lived perennial waft a pleasant fragrance. A reliable (and sometimes prolific) self-sower, it comes in several forms, including white-flowered and gold-leaved varieties. Dalliances with other species including the East Asian native Agastache rugosa have led to numerous hybrid selections (e.g., ‘Blue Fortune’), most of which offer a somewhat more compact habit.

Tall larkspur (Delphinium exaltatum)

These larkspurs are more delicate their hybridized European cousins.

Common garden delphiniums are European hybrids of Eurasian species that melt in the heat and humidity of eastern North American summers. Tall larkspur, in contrast, hails from the Southeast United States, so it can take just about anything summer throws at it. Don’t expect flowers the size of those of the prima-donna hybrids. Count instead on spikes of purple-blue blooms that are much daintier and less flop-prone, on 4- to 5-foot stalks. They’re right at home in cottage borders, butterfly borders, and other informal settings. Flowering kicks in around the Fourth, yet another reason to celebrate the holiday.

Surefire Perennials for Shadier Gardens

Bowman’s root is an underused perennial that tolerates both sun and some shade.

Where have all the flowers gone? If your shade garden has you asking this question around late June, you might consider adding a few of the following perennials to your plantings. They’ll answer the “where have they gone” question with an emphatic “They’re still here!”.

Of course, even the most shade-tolerant perennial may languish if conditions are too dark, dry, or lean. You can improve impoverished or overly heavy soil by digging in a couple of inches of Fafard Premium Natural & Organic Compost before planting your new prizes. In areas with very dense low shade from overhead branches, consider removing a few of the branched culprits.

American Ipecac and Bowman’s Root

Gillenia trifoliata is a much underused native perennial wildflower whose fall color is as spectacular as its blooms.

American ipecac and Bowman’s root (Gillenia stipulata and Gillenia trifoliata), which also goes by the botanical name Porteranthus, is a durable shade- and drought-tolerant eastern U.S. native that starts summer with a flurry of starry white flowers on bushy, feathery-leaved, 3-foot plants. As with many of the best garden perennials, they’re rarely available because of their incompatibility with the mass-market plant production mill that dominates most of American horticulture these days (click on the plant name links for good sources).

Gillenia takes a while to get going, and they look doughty on a garden center display bench. Don’t let this deter you. Once they’re up to size, they’ll anchor your shade border for decades with their ferny presence and delightful June-to-July blooms. They’ll also go out with a fiery salvo each fall when their leaves turn sunset tones of purple, orange, and yellow. Few perennials offer so much beauty for so little effort.

Poke Milkweed

Poke milkweed opens its starburst clusters of down-facing white flowers on 4-foot stems in early summer. (Image by D. cerulea)

Bummed because your garden is too shady for milkweed and its attendant monarch butterflies? Good news: it probably isn’t. You just need to grow the delightful milkweed species that naturally occurs in woodland edge and clearings throughout much of the eastern United States, poke milkweed (Asclepias exaltata). It opens its starburst clusters of down-facing white flowers on 4-foot stems in early summer, making an excellent complement to Gillenia, for one. The common name of this clumping, noninvasive perennial refers to the large elliptical leaves, which bear something of a resemblance to pokeweed (Phytolacca americana). Plants sometimes go dormant in late summer, so don’t be alarmed if it dies back a few weeks after blooming.

Yellow Fumitory

Shade gardens light up with the bright yellow flowers of this fumatory.

We profiled the little charmer, yellow fumitory (Corydalis lutea), in last month’s piece on long-blooming perennials. Whether in sun or shade, it bears repeat flushes of golden-yellow flowers from spring to fall atop handsome 10-inch hummocks of lobed blue-green leaves. Plants multiply reliably via self-sown (or rather ant-sown) seedlings.

Black Cohosh and Appalachian Bugbane

Black cohosh produces white wands of flowers that look very pretty in early summer.

Two big bodacious perennials for partial shade are black cohosh and Appalachian bugbane (Actaea racemosa and A. rubifolia). These two eastern U.S. natives produce imposing bottlebrush spikes of white flowers that entice summer bees and wasps with their pungent (but pleasant) mineral fragrance. The spikes can tower as high as 5 or 6 feet in sites with fertile moist soil (although Appalachian bugbane tends to be somewhat shorter than its compatriot). Robust shrubby clumps of compound foliage provide the foundation for this floral majesty, with Appalachian bugbane making a bolder statement thanks to its large, maple-shaped leaf segments.

August Lily

August lily opens its large fragrant funnel-shaped flowers in midsummer.

Hostas are sometimes referred to as “flowering foliage plants”. This species is one of the main reasons why. As the common name suggests, August lily (Hosta plantaginea) opens its large fragrant funnel-shaped flowers in midsummer, on stout stems that rise above the lush clumps of creased, yellow-green, 10-inch-wide leaves. Hybrids include lilac-flowered ‘Honeybells’, and ‘Royal Standard’, which complements its white flowers with rich green leaves. All forms and hybrids of the species are relatively sun-tolerant.

Turtlehead

The flowers of these eastern North American natives do indeed resemble something you’d find at the north end of a turtle.

Even the most earthbound imagination will readily grasp what the common name is about, for the flowers of these eastern North American natives do indeed resemble something you’d find at the north end of a turtle. All are tall, moisture-craving, shade-tolerant perennials that bloom in summer. Chelone glabra starts things off in July with white “heads” poised at the tips of 3- to 6-foot stems. Two other widely available species – Chelone obliqua and C. lyonii – offer rose-pink flowers a bit later in the season. The compact cultivar Chelone obliqua ‘Tiny Tortuga’ carries its bright pink flowers on slowly spreading, glossy-leaved plants that top out at around 18 inches tall.

Cardinal Flower and Great Blue Lobelia

Lobelia cardinalis thrives with lots of moisture and dappled shade.

If you love hummingbirds, you need some of these eastern North American natives in your garden. Cardinal flower sports brilliant red hummer-magnets in August, just about the time great blue lobelia decks itself with (you guessed it) bright blue blooms. Both stand around 3 feet tall in flower, dying back to evergreen rosettes after blooming.

Native to damp woodland edges and the like in the wild, Lobelia cardinalis thrives with lots of moisture and dappled shade. Lobelia siphilitica is more drought- and sun-tolerant, but also grows happily in part shade. Cardinal flower comes in many forms including some with purple leaves (e.g., ‘New Moon Maroon’) or white or pink flowers. It also has occasional dalliances with great blue lobelia that result in typically purple-flowered hybrids classified as Lobelia x gerardii. These are well worth seeking out, as is another comely blue-flowered eastern North American native, Lobelia spicata.

Yellow Sages

Jupiter’s distaff (Salvia glutinosa) is a European native with yellow flowers that attract bees.

Not all perennial sages are blue-flowered sun-lovers. Several Eurasian salvias have yellow flowers and a preference for shade. Salvia koyamae sends up spikes of pale yellow flowers in late summer, over handsome 18-inch clumps of bold heart-shaped leaves. Also well worth growing is Jupiter’s distaff (Salvia glutinosa), a European native that’s larger than Salvia koyamae in all its parts. A first-rate foliage perennial, it’s particularly effective during its early- to mid-summer blooming season.

Yellow Toad Lily

This toadlilies yellow, maroon-speckled flowers bloom in July and August.

Most toad lilies flower from the end of summer into fall. Not so with the Japanese native, Yellow Toad Lily (Tricyrtis latifolia), whose 2-foot stems are decked with erect branching clusters of yellow, maroon-speckled flowers in July and August.

Grapeleaf Anemone

Silver-pink, saucer-shaped blossoms toss in the August breeze on branching 3- to 4-foot stems.

Like yellow toad lily, Grapeleaf Anemone (Anemone ‘Robustissima’) is an anomalously early-blooming member of a group of perennials (hybrid Japanese anemones) that typically flower in late summer and fall. The silver-pink, saucer-shaped blossoms toss in the August breeze on branching 3- to 4-foot stems. Plants grown from questing underground rhizomes that eventually form large colonies. Exceptionally sun-tolerant compared to most Japanese anemones, it thrives in full sun to half shade.

Garden Perennials That Don’t Stop Blooming

As flowering plants, most perennials are a mixed blessing. To their credit, they produce some of the garden’s signature blooms, on plants that return reliably year after year. What would spring be without primroses and trilliums, or summer without bee-balm and black-eyed Susans, or fall without asters and Japanese anemones?

Seasonality of bloom does have its downside, however. Many perennials are as fleeting as they are beautiful, flowering for a mere 2 or 3 weeks. Many – but not all. Here are some of our favorite perennials that depart from the norm by blooming for 3 months (or more) rather than the typical 3 weeks. Most will.

Nonstop Flowering Perennials

Yellow Fumitory (Corydalis lutea, aka Pseudofumaria lutea)

The bright yellow flowers and delicate blue-green leaves of this fumatory bring season-long color to gardens.

Few shade-loving plants of any type flower as brightly and as tirelessly as this somewhat short-lived perennial from mountains of central Europe. The golden-yellow, sharks-head-shaped flowers occur on mounded, ferny-leaved, foot-tall plants from mid-spring to fall, with barely a pause. Plants often generously self-sow, assisted by ants that distribute the seeds. Not to worry: unwanted seedlings are easily pulled – but you’ll likely want to keep all or most of them. Yellow fumitory is a perfect fit for shady cottage gardens and other semi-informal settings, mixed with celandine poppies (Stylophorum diphyllum), creeping phlox (Phlox stolonifera), ferns, hostas, zigzag goldendrod (Solidago flexicaulis), and the like.  USDA hardiness zones: 5 to 8

Kenilworth Ivy (Cymbalaria muralis)

The ever-flowering Kenilworth ivy grows beautifully along rock walls and between paving stones.

Another shade-loving European native, Cymbalaria muralis does indeed resemble a miniature ivy in its lobed near-evergreen leaves and its clambering growth. Its small blue snapdragon-like flowers depart completely from the ivy model, however. The trailing plants grow best in well-drained soil, quickly covering the ground or a wall, and flowering happily from early spring to late summer. Plants can become a nuisance in favorable climates, so use with caution in areas such as the Pacific Northwest. The similar Cymbalaria pallida spreads less vigorously, forming condensed mats spangled with mid-blue flowers (or white, in the case of ‘Albiflora’). Both are hardy from zones 5 to 8.

Geranium ‘Rozanne’

‘Rozanne’ forms attractive mounds and blooms effortlessly through summer.

Few perennials flower as unceasingly as this hybrid geranium. Happy in full sun to light shade, it produces violet-blue saucer-flowers from late spring through summer on lax continually lengthening stems. You can shear plants to a few inches from the ground in midsummer to keep them more compact and to stimulate more prolific late-season bloom. The 2008 winner of the Perennial Plant Association’s Perennial of the Year award, ‘Rozanne’ has become immensely (and ubiquitously) popular throughout its USDA zone 5 to 8 hardiness range. (True Geranium are distinct from florists’ “geraniums”, which actually belong to the genus Pelargonium).

Corsican Violet (Viola corsica)

Corsican violets and delicate year-long bloomers.

Small in stature but unsurpassed in flower power, Corsican violet blooms continuously year-round, pausing only during sub-freezing winter spells. The violet-blue, white-eyed flowers lift their faces to the sun atop low semi-trailing stems that ultimately extend to 5 or 6 inches. Give this delightful little urchin a place in a sunny well-drained garden niche in its Zone 5 to 10 hardiness range and it will give you virtually endless delight. If you leave a few seedheads you’ll also get a few volunteer plants to spread the cheer.

Lavender (Lavandula hybrids)

Some lavender varieties will bloom from June to early October.

While technically a dwarf shrub, lavender functions as a herbaceous perennial in cold-winter areas of the U.S., where it typically flowers from late spring until late summer. Some lavender varieties take it a few weeks further, blooming into early fall. Among the best of these floriferous selections are 2-foot-tall ‘Royal Velvet’ and the 10-inch dwarf ‘Super Blue’. Also well worth seeking out are hardy hybrids between common lavender and Lavandula latifolia (known collectively as lavandin or Lavandula × intermedia). The lavandin cultivar ‘Phenomenal’ earns its name by producing numerous 2-foot lavender-blue spires on hardy silver-leaved plants from June to early October. It shares common lavender’s Zone 5 hardiness, given a sunny well-drained niche.

Dalmatian Toadflax (Linaria dalmatica)

The non-invasive Dalmatian toadflax is drought-tolerant and blooms endlessly.

Don’t be deceived by the superficial resemblance to the weedy Linaria vulgaris, aka butter and eggs. This is a totally different toadflax, forming non-spreading clumps of 30-inch stems furnished with attractive blue-green foliage and topped from early summer to frost with spikes of lemon-yellow snapdragons. A beautiful drought-tolerant thing, it prospers in hot sunny well-drained garden habitats in zones 4 to 9, self-sowing moderately where happy. It can be a bit too happy in parts of the Western U.S., so check your state’s invasive-plant list.

Phlox ‘Solar Flare’

A hybrid between two native phlox species, ‘Solar Flare’ bears pink-eyed flowers in flushes from spring to fall.

A hybrid of the eastern U.S. native Phlox carolina, this disease-resistant cultivar opens its white, pink-eyed flowers in late spring, weeks before those of garden phlox (Phlox paniculata). It follows with repeated flushes throughout summer and into fall, provided it’s regularly deadheaded. Other laudable features include a compact habit (2 feet tall and 1 foot wide) and exceptional disease resistance. It’s a reliable performer in full sun to light shade in zones 4 to 8. Apply an inch of Fafard organic compost in spring and your ‘Solar Flare’ will be especially dazzling.

Daisy Mae Mongolian Daisy (Kalimeris integrifolia ‘Daisy Mae’)

Clouds of little white yellow-eyed daisies adorn the 2-foot, clumping stems of ‘Daisy Mae’ from early summer until frost. Full to part sun and well-drained soil are all it requires. Use it in borders and containers, perhaps in combination with other sun-loving, drought-tolerant perennials such as winecups (Callirhoe involucrata) and balloon flower (Platycodon grandiflorus). Hardy from zones 5 to 9.

Gaura (Oenothera lindheimeri)

The prairie-native, Gaura, blooms nonstop and is a butterfly favorite.

Also known as Gaura lindheimeri, this prairie native keeps on blooming through heat and drought from early July to frost. The butterfly-shaped blooms are arrayed along wiry 3-foot wands that toss in the summer breeze. Typically white-flowered (as in the excellent variety ‘Whirling Butterflies), it also comes in pink forms (including ‘Pink Cloud’ and ‘Siskyou Pink’). Given a porous soil in full sun, it will reliably winter from zones 5 to 9.

Sweet Spring-Garden Primroses

Cowslips are easy-care European native wildflowers that lend a cottage-garden look to spring beds.

Primroses (known botanically as Primula) have a reputation for being garden prima donnas. Often, this characterization is deserved. Many Primula are fussy garden dwellers at best, hailing from specialized habitats such as alpine crevices and glacial screes. Don’t let this fact keep you from the numerous easily cultivated and highly rewarding members of the genus, however. If you have some shade (or in some cases, even if you don’t) and you’re somewhere in USDA Hardiness Zones 4 to 8, there’s likely a primrose for your garden. Of course, you’ll want to amend any sandy or heavy clay soil with a good helping of Fafard® Premium Natural & Organic Compost.

Drumstick Primrose (Primula denticulata)

The drumstick blooms of this primula are fun and good for cutting.

The primrose season starts in late winter or early spring with this adorable but surprisingly tough little elf from the Himalayas. The common name refers to the ball-shaped flower cluster that forms the business end of the imaginary “drumstick”. The 4-inch flower stem comprises the stubby “stick”. A rosette of toothed, oval, up-angled leaves collars the base of the stick (as is the case with most of the other primroses described below). Primula denticulata blooms in a wide range of colors, from the typical mauve-purple through shades of white, pink, red, and violet-blue. The all-white ‘Alba‘ is easily found in nurseries as is traditional pink. A not-too-dry soil in part shade is ideal, but it will do fine in moist sunny niches in USDA Hardiness Zones 4 through 7.

Common Primrose (Primula vulgaris)

Though bred in many wild colors, the traditional common primrose bears pale yellow flowers with a darker eye.

In the wild, this cherished European native bears individual yellow flowers on 4- to 6-inch stems over clumps of somewhat radish-like leaves. In cultivation, it’s been selected and hybridized into numerous hues, often with the “wild” yellow coloration confined to a central eye. Many vulgaris spinoffs produce clustered rather than individual blooms. Most notable of these are the popular Polyanthus hybrids (Zones 4-8), which flower in a rainbow of colors from rich red to deep blue. Flowers of “acaulis” hybrids – another swarm of primroses derived from Primula vulgaris – are singly borne. Among the best of the acaulis hybrids are the Juliana primroses, a swarm of miniature cultivars involving the diminutive species Primula juliae. The earliest vulgaris hybrids and forms (including the Julianas) bloom with the drumsticks in late winter and early spring, but some varieties flower weeks later. Many are sweetly fragrant, adding further sensual delight to the early-season garden. Partial shade and humus-rich soil are ideal for all forms and hybrids of this storied species.

Cowslip (Primula veris)

Cowslips are carefree garden flowers for spring.

Another European native treasured and cultivated since ancient times, cowslip (Zones 3-8) is instantly recognized by its signature lopsided clusters of nodding yellow to red flowers that are corseted with funnel-shaped bracts for much of their length, with the petals flaring at the tips. Their form and presentation lend them a lovably disheveled look, ideally suited for cottage gardens and other informal settings in partial shade to moist full sun. Named selections include ‘Coronation’, a seed-grown strain with relatively large yellow, orange, or red flowers (‘Sunset Shades’ is similar). The subspecies macrocalyx also has larger flowers that tend toward orange. All forms of cowslip flower a bit later than most of the vulgaris primroses, in early to mid-spring. They’re also quite lime-tolerant, doing well in acid to slightly alkaline soil.

Oxslip (Primula elatior)

Oxslips are fuller, larger, and more symmetrical than cowslips.

Europe gives us a third eminently growable yellow-flowered primrose species, Primula elatior (Zones 3-8). The scentless, straw-yellow blooms flare more broadly at the tips than those of cowslip, and are presented in fuller, more symmetrical clusters. Flowering time and soil preferences are much the same as cowslip’s.

Cherryblossom Primrose (Primula sieboldii)

Cherryblossom primrose comes in lots of pleasing pink and white shades.

Primula saves some of its most spectacular displays for late spring, as exemplified by this highly adaptable, multi-splendored East Asian native. In mid to late May cherryblossom primrose (Zones 4-8) throws abundant clusters of showy, starry blooms that arise from spreading clumps of scalloped leaves. The typically wedge-shaped petals are variously cut and fringed and crimped, depending on the variety. Flower color ranges from pink to purple to blue to white, often with contrasting striping. It’s for good reason that Japanese gardeners have selected and named hundreds of cultivars of cherryblossom primrose over the centuries. A few of these so-called Sakurasoh hybrids are available in the U.S. and are well worth seeking out. But any form of Primula sieboldii makes an excellent addition to a partly shaded, acidic garden niche. Plants are early-dormant in summer and late to arise in spring, so be sure to remember where you planted them!

Candelabra Primrose (Primula japonica)

Japanese of candelabra primroses grow best in moist soil.

Actually, there are many candelabra primrose (Zones 4-8) species, all flowering gloriously in late spring – but this is the quintessential one. The common name comes from the tiered whorls of flowers borne candelabra-fashion on 2- to 3-foot stems, over shaggy clumps of large puckered leaves. Primula japonica usually flowers in red (as in ‘Miller’s Crimson’), but white and pink forms also occur (including ‘Postford White’ and ‘Apple Blossom’). Other candelabra species venture into other parts of the spectrum, including yellow (Primula bulleyana) and lavender-purple (Primula beesiana). Hybridization readily occurs between varieties and species, so plant only one if you don’t want mongrel seedlings. All candelabra primroses thrive in humus-rich, damp to boggy soil in part shade or sun.

Any one of these Primula would make a wonderful, carefree addition to your spring garden. If you think all primroses are prima donnas, you’re in for a pleasant surprise.

Wonderful Wood Sorrel for Pots and Gardens

Wonderful Wood Sorrel for Pots and Gardens Featured Image
Candy cane sorrel (Oxalis versicolor) is named for its white flowers with red edges.

Wood sorrels – known botanically as Oxalis – include some of our most familiar and most annoying garden weeds. But this circumglobal genus has its good side too, encompassing dozens of outstanding garden and greenhouse plants.

Saint Patrick’s Shamrock

Purple-leaved Oxalis triangularis subsp. papilionacea
The purple-leaved Oxalis triangularis subsp. papilionacea, is one of the best-known forms.

One such Oxalis makes a ritual appearance in many upscale grocers, garden centers, and other similar locations around St. Patrick’s Day, where it’s sold by the thousands as Irish “shamrocks”. With its bold three-lobed leaves – resembling an oversized clover – false shamrock (Oxalis triangularis, sometimes listed as Oxalis regnellii) absolutely fits the part. This native of rocky streamside habitats from Brazil to Paraguay is anything but Irish, however. It’s also not a clover, belonging to an entirely different branch of the plant family tree. Still, it makes a splendid, long-lived container plant (and faux shamrock), both in its green-leaved form and in enticing variants, such as purple-leaved subsp. papilionacea and silver-splashed ‘Irish Mist‘.

All forms of the species produce year-round flushes of lush foliage and pinkish flowers, arising from scaly underground rhizomes that resemble miniature pinecones. An easy keeper, Oxalis triangularis favors semi-shade, moderate water, and a relatively porous, humus-rich potting medium such as Fafard Professional Potting Mix. It often does well with a dryish rest in winter, mimicking seasonal conditions in its native haunts. It’s also remarkably hardy as a garden plant, surviving winters as cold as USDA Hardiness Zone 7.

Iron Cross Sorrel

Iron Cross Sorrel
Bold leaves and pretty pink summer flowers make this an excellent sorrel for potting.

A couple of other Central and South American species sometimes turn up in garden centers and catalogs. Noteworthy for its bold four-parted leaves, Oxalis tetraphylla is commonly grown in its “iron cross” form, with bold purple blotches marking the base of each leaflet. A summer-grower, it gives a good show in a planter, pot, or in a partly shaded garden niche in Zones 8 to 10, sending up sprays of bright purple-pink flowers from July onward.

Silver Shamrock

Silver Shamrock with flowers

Silver false shamrock (Oxalis adenophylla (Zones 7-9), from high altitudes in Chile and Argentina, is another South American species often sold in catalogs. It is a bit of a mystery, considering its trickiness in cultivation. It needs relatively mild winters and cool summers to succeed, or a reliable snow cover in cold-winter areas. Give it porous soil in any case, to mimic the gravel slopes it calls home.

South African Sorrels

Bowie's wood sorrel
Bowie’s wood sorrel is a real beauty with large pink flowers and leathery green leaves.

Ornamental Oxalis species have their epicenter in another sub-equatorial region – the South African Cape. Dozens of Oxalis, with flowers and foliage in a rainbow of beguiling hues, come from this florally blessed locale. Almost all South African forms are winter-growers, arising from small underground bulbs in mid-to-late fall and flowering for weeks or months before returning to dormancy in spring. Ample sun, relatively cool air, and not overly moist soil are their only requirements, whether grown in a pot or in a favorable garden climate (such as coastal California). They can go entirely without water during their summer dormant period. Notable South African species include:

  • Bowie’s wood-sorrel – Oxalis bowiei, whose clumps of large leathery rich-green “shamrocks” give rise to rose-pink flowers in late winter and spring.
  • Compressed wood-sorrel – Oxalis compressa, which produces bright yellow flowers in winter over mounds of clover-like leaves. The cultivar ‘Pom-Pom’ has fully double flowers like miniature chrysanthemums.
  • The shrubby Oxalis livida, whose botanical name refers to the liver-purple tinge of its finely divided leaves.
  • Yellow-eyed sorrel – Oxalis obtusa is an amazingly diverse species that flowers for many weeks in mid-to late-winter in colors ranging from white to pink to purple to yellow.
  • Palm-leaf sorrel – Oxalis palmifrons is named for its glistening silver-furred leaves that do indeed resemble tiny palm fronds.
  • Purple sorrel – Oxalis purpurea, which rivals Oxalis obtusa in the color range of its dazzling yellow, pink, purple, lavender, or white flowers.
  • Candy cane sorrel – Oxalis versicolor is named for its appearance when its white, red-edged petals are furled. As with all South African oxalis, the flowers open wide only in bright sunlight.
Oxalis triangularis 'Irish Mist'
Oxalis triangularis ‘Irish Mist’ has beautiful mottled leaves and white flowers.

Cold-Hardy Sorrels

A few ornamental oxalis are suitable for cold-climate gardens. The plant often sold as pink wood sorrel (sometimes named Oxalis crassipes or Oxalis rosea, but actually a form of Oxalis articulata (no matter)) is one of the best ground covers for sunny or lightly shaded Zone 6 to 9 gardens. It spreads gradually into lush clumps of typically oxalian clover-like leaves, spangled much of the growing season with rose-pink flowers. A white-flowered form is also sometimes available and well worth seeking out.

Oxalis violacea
Oxalis violacea is a U.S. native that exists from the Eastern Seaboard to the Rocky Mountains.

For sunny to partly shaded rock gardens, troughs, and other similar settings in Zones 4 to 8, there’s the U.S. native violet wood sorrel (Oxalis violacea), which is found in prairies, ledges, and other dryish habitats from the Eastern Seaboard to the Rockies. It’s a delightful little thing, forming tufts of purple-flushed mini-shamrocks, studded in late spring with pink flowers. The rarely available mountain wood sorrel (Oxalis montana), from uplands of the eastern U.S., is similar to Oxalis violacea in appearance but more vigorous in growth if given a cool shaded niche with humus-rich soil in Zones 3 to 7. Curiously, it’s rarely offered in nurseries, despite its ability to form attractive ground-covering clumps of dainty foliage.

Golden Sorrel

Molten Lava™ (Image by Proven Winners™)
Molten Lava™ is a compact accent plant for containers. (Image by Proven Winners™)

Two cheerful varieties of golden sorrel (Oxalis spiralis) have become quite popular for container plantings. These are the dark-burgundy-leaved Zinfandel™ and the brilliant orange-purple-and-yellow-leaved Molten Lava™. Both plants form low-growing mounds and develop yellow flowers in summer. They are hardy in Zones 9-11.

Whether for greenhouse or garden, ornamental Oxalis have plenty to offer in the way of handsome colorful foliage and charming and often dazzling flowers. Wood sorrels are so much more than weeds – or St Patrick’s Day curiosities.

Landscape Your Home With Fruiting Edibles!

Landscape Your Home with Fruiting Edibles! Featured Image

Edible landscaping can be a kick – especially if you take full advantage of the dizzying diversity of fruiting trees and shrubs. While old-time (and often pest-prone) favorites, such as apples and pears, certainly have their place, so too do scores of lesser-known but equally rewarding fruit-bearing species, including those portrayed below. They’ll bring excitement and new flavors to your garden – as well as fewer pest problems than those ubiquitous old-timers. And many of them are beautiful to boot (which can’t be said of most apple and pear trees).

Carpeting Cranberries

Home-grown cranberries
Home-grown cranberries are rewarding and ecologically friendly.

Home-grown cranberries (Vaccinium macrocarpon, USDA Hardiness Zones 2-7) are so much more rewarding and ecologically friendly than market-bought ones. Even better, the plants that bear them are highly ornamental, their creeping stems weaving into dense ground-covering swaths of dainty glistening evergreen foliage. Give this North American native a moist humus-rich acidic soil and ample sun, and it will steadily spread into a 3-foot-wide, 6- to 8-inch-high hummock that covers itself in ornamental red berries in late summer.

Commercial cranberry varieties such as ‘Stevens’ produce especially heavy crops. Where space is limited, consider the dwarf cultivar ‘Hamilton’, which tops out at a foot wide and 4 inches high, but with normal-size berries. Plant two or more different varieties for maximum berry production. Native mostly to latitudes north of the Mason-Dixon Line, cranberry does best in areas with chilly winters and relatively unoppressive summers. Dig a couple of inches of Fafard Ultra Outdoor Planting Mix into the soil before planting, and your cranberries will be extra-happy.

Lingonberries
Lingonberry is similar to cranberry in habit, foliage, preferred garden habitat, and culinary uses.

Also effective (and productive) as a small-scale ground cover is cranberry’s close cousin, lingonberry (Vaccinium vitis-idaea, zones 3-7). Similar to cranberry in habit, foliage, preferred garden habitat, and culinary uses, it bears clusters of pale-pink, urn-shaped flowers in late spring and summer that ripen to tomato-red pea-sized fruits in late summer and fall. Lingonberries going by the name of Koralle yield abundant fruits on spreading 8- to 12-inch-tall plants. The vigorous, large-fruited cultivar ‘Red Pearl’ grows a few inches taller and wider than Koralle.

Harvestable Hedges

Black chokecherries
Black chokecherry fruits are excellent for preserves, pies, and other kitchen uses.

A significant food crop in Europe, the eastern North American native Aronia melanocarpa (commonly known as black chokeberry) is surprisingly absent from American orchards and gardens. Yet this rugged deciduous shrub makes an outstanding ornamental and culinary plant for sunny niches throughout USDA Zones 3 to 8. Plants typically form suckering 3- to 5-foot-tall clumps clad with glossy-green oval leaves that turn brilliant sunset shades in fall. Abundant clusters of white flowers open toward the branch tips in mid-spring, followed by tart-flavored, quarter-inch-wide berries that ripen black-purple in late summer. The fruits are excellent for preserves, pies, and other kitchen uses. With its dense habit, black chokeberry works wonderfully as a low garden or boundary hedge.

Commercial cultivars such as ‘Viking’ (which may be a hybrid with mountain ash, Sorbus aucuparia) produce the largest berries, on vigorously suckering stems. For residential gardens, ‘Autumn Magic’ and Iroquois Beauty™ are of relatively compact growth with somewhat smaller – but still toothsome – berries. Two newly introduced cultivars (Ground Hug™ and Low Scape Mound®) from the University of Connecticut’s breeding program are even more compact, maturing at 1 to 2 feet tall and producing modest crops of fruit. For maximum production, plant more than one cultivar of black chokeberry.

Beach plums
These fruits may small, but they’re unsurpassed for flavoring preserves, syrups, and vinegars.

The tart, grape-sized fruits of beach plum (Prunus maritima) may be small, but they’re unsurpassed for flavoring preserves, syrups, vinegar, and the like. Thousands of beach plum aficionados descend on Eastern Seaboard dunes in August and September to harvest the red-purple ripe fruits. Curiously, however, very few gardeners in beach plum’s Zone 3 to 8 hardiness range recognize its considerable merits as a culinary and ornamental plant.

Although a rather scraggly 3- to 5-foot thing in its native dune habitats, in average garden soil it forms a dense 6- to 12-foot clump well-suited for hedging. Blizzards of white flowers in mid-spring are followed by fruits if another beach plum is nearby for cross-pollination. Most plants bear irregularly from year to year, so look for selections – such as ‘Premier’ and ‘Jersey Beach Plum’ – that are more consistent producers. Cultivars ‘Nana’ and ‘Ecos’ bear reliable annual crops on more compact 3- to 5-foot-tall plants. You can further enhance beach plum’s productivity and habit by thinning out old, unproductive branches in early spring (this also works for the other shrubs described here).

Saskatoon berries
Saskatoon bears blueberry-like, early-summer fruits in easy reach.

From upper latitudes of western North America comes another first-rate hedging and fruiting shrub, Amelanchier alnifolia ‘Regent’. A compact selection of one of several small native tree species variously known as serviceberry and shadblow, ‘Regent’ tops out at a bushy 6 feet tall, placing its blueberry-like, early-summer fruits in easy reach. Clusters of gossamer white flowers precede the fruits in the earliest spring. Commonly known as saskatoon, this extremely cold-hardy shrub thrives in full sun to light shade and most types of soil from Zones 2 to 7. Plant another variety of Amelanchier nearby to maximize fruiting.

Honeyberries
Fleshy, tasty honeyberries have similar uses to those of blueberry and saskatoon.

Also producing blue fruit in early summer is honeyberry, Lonicera caerulea. Olive-shaped rather than rounded, the fleshy, tasty berries have similar uses to those of blueberry and saskatoon. They’re borne on attractive 3- to 4-foot plants clothed with dainty, downy, oval leaves that flush just before the pale yellow flowers open in early spring. You’ll need more than one variety for plants to produce fruit, so why not make a hedge of them? Several cultivars of this extremely hardy (Zones 2 to 7) Northeast Asian native are available, including Blue Moon™, Blue Velvet Palm, and Yezberry Sugar Pie®. All prefer full sun but will tolerate some shade.

Nanking cherries
Red, tart to sweet, cranberry-sized Nanking cherries appear in late spring or early summer.

East Asia is also the home of Nanking cherry (Prunus tomentosa), another little-known and highly ornamental fruiting shrub. Its upright to arching stems carry pale pink flowers along nearly their entire length in early spring, before the toothed oval leaves expand. Red, tart to sweet, cranberry-sized “cherries” follow in late spring and early summer, ready for fresh-eating or for making into pies or preserves. Maturing at around 8 feet high and slightly wider, Nanking cherry nicely fills the bill as a large hedging plant for sunny sites in Zones 2 to 7. When available (which is all too rarely), it’s usually offered as unnamed seedlings. Multiple plants are needed for a good fruit-set.

Trend-Setting Fruit Trees

Pawpaw's fruit
The flavor of a pawpaw’s custardy fruits varies from tree to tree.

The standard suburban fruit tree is a rather homely, disease-riddled affair. A well-grown specimen of pawpaw (Asimina triloba) is anything but. In its native woodland haunts in the central and southeastern U.S., it grows as a gaunt, unprepossessing understory tree. It’s another thing entirely in a sunny or lightly shaded garden niche, where it typically forms a dense low-branched 15- to a 20-foot tree whose conical crown is densely furnished with large tropical-looking leaves. Curious fleshy liver-purple flowers in early spring give rise to large, potato-shaped fruits that ripen in late summer (two or more varieties are needed for fruiting to occur).

The flavor of the fruits’ custardy flesh varies from tree to tree, as does the number of seeds it contains, so look for varieties that have been selected for their fruiting characteristics. Young pawpaw trees suffer in harsh wind and blistering heat and should be sited or protected accordingly. The Zone 5 to 9 hardiness of this central and Southeast U.S. native belies its tropical appearance.

Chinese quince

Also bearing large tasty fruit on handsome small trees is Chinese quince, Pseudocydonia sinensis. Fragrant bright yellow quinces dangle from its rounded crown in late summer, not long before the leaves turn burgundy and orange. This East Asian native is also well worth growing for its pink sweet-scented mid-spring flowers and for its handsome bark that flakes into multi-colored patches. Plants are self-fruitful, so you only need one tree to get the tart fruits, which are delicious in preserves and baked goods. Chinese quince does well in Zones 5 to 9 in full sun and fertile loamy soil.

Female Chinese-peppercorn fruit
Spicily aromatic, reddish-brown, pepper-like fruit capsules mature in late summer on female Chinese-peppercorn trees.

If your taste buds have ever thrilled with the zingy flavor of Szechuan peppercorns, you should also be thrilled to know that the species that bears that Chinese-peppercorn fruit (Zanthoxylum simulans) makes a striking small tree for the culinary garden. Its spiny trunk and branches grow rather rapidly into an open 15- to 25-foot specimen that becomes characterfully gnarled with age. Pinnate leaves similar to those of mountain ash unfurl in early spring, a few weeks before the inconspicuous clusters of greenish flowers appear. Spicily aromatic, reddish-brown, pepper-like fruit capsules mature in late summer on female plants, which are usually somewhat self-fruitful. Plants offered for sale tend to be self-pollinated seedlings of such female plants, which do not need a male companion to produce peppercorns. Zanthoxylum simulans thrives in sun and well-drained soil from Zones 6 to 9. It functions as a large shrub in Zone 5, where it sometimes dies back in winter.

If you’re looking to literally add distinctive character to your edible landscape this spring, any of the above would be the perfect place to start. There’s always plenty of room to explore in the garden!