Archive: Aug 2018

  1. Top 10 Tough Fast-Growing Shade Trees

    What makes a fast-growing shade tree exceptional? First, it must be strong-wooded and long lived. Second, it must be attractive, providing desirable seasonal characteristics to make your yard look great. Those that are native, disease resistant, and well-adapted to a given region are also optimal. Finally, they should have minimal messy fruits to reduce the …

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  2. Rose Rosette Disease Solutions

    Few rose diseases are more dreaded than rose rosette disease. This disfiguring, deadly pathogen can take a perfectly lovely rose from glory to ruin in just a season or two. It’s very easy to identify, but trickier to manage. Thankfully, there are solutions for ardent rose growers. Sometimes the best way to learn about a …

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  3. Luscious Lilies of Late Summer


    Tiger lilies (Lilium lancifolium) are spectacular tall bloomers that appear in late summer. (Photo by Jessie Keith)

    Most gardens can use a visual lift in the dog days of late summer.  This is where late-blooming lilies come in.  When their voluptuous, often deliciously scented blooms make their grand entrance in July and August, it’s like a royal fanfare in the landscape.  Goodbye, garden doldrums.

    About Late-Summer Lilies

    The raspberry-pink-flowered Lilium speciosum is a lovely species lily for the garden. (Photo by Jessie Keith)

    Thanks to the efforts of breeders, late-blooming lilies flower in a wide spectrum of luscious colors, from white to yellow to pink to red, with all manner of hues in between.  They also come in many sizes, with the smallest measuring only a foot tall and the grandest towering to 6 feet or more.  While the former are useful for containers and bedding schemes, it’s the giant late-blooming hybrids that are the true glory of the dog-day garden.  Their enormous clusters of large, sumptuous blooms on eye-high stems are almost beyond belief (as is the fact that they grow from relatively modest-sized, scaly bulbs).Natural and Organic

    Better yet, they’re easily cultivated, with most lilies thriving in full sun and fertile, humus-rich, well-aerated soil in USDA Hardiness zones 5 through 8 (excessively sandy or clay-heavy soil should be amended with a good compost, such as Fafard Premium Natural and Organic Compost).  All bets are off, however, in areas that host the dreaded red lily beetle.  Where this insect abounds (mostly in the Northeast), lilies can be more of a chore than they’re worth, requiring hours of hand-picking of the glossy scarlet adults and their repulsive, excrement-coated larvae.  In other parts of their hardiness range, lilies have few enemies, although viruses and large herbivores (particularly deer) can sometimes cause problems.

    Trumpet Hybrids

    Oriental Hybrids come into prominence in early August. (Photo by Jessie Keith)

    The summer lily season opens in spectacular style with the stately Trumpet Hybrids, renowned for their gigantic, fragrant, funnel-shaped blooms that take after the Chinese native Lilium regale.  The popular Golden Splendor Strain produces 6-foot spires of rich lemon-yellow trumpets with burgundy-stained exteriors, while the equally popular (and showy) Pink Perfection Strain sports rose-pink funnels with gold throats.  Many other splendid Trumpet Hybrids are offered by bulb merchants (including several that specialize in lilies).  Lilium regale itself is well worth growing for its immense white flowers with maroon reverses (pure white forms are also sold).

    Some hybrids in the Trumpet tribe have nodding, mildly scented, “Turks-cap” flowers that evoke the group’s other important ancestor, Lilium henryi.  Among the best and most widely offered of these is ‘Lady Alice’, with white, purple-flecked, gold-starred flowers on 4- to 6-foot stems. There are also several common species worth seeking out.  The classic “tiger lily” (Lilium lancifolium), with its black-spotted blooms of clear orange, is tall, clumping, and looks its best in August.

    Oriental Hybrids

    Pink Oriental lilies in a late-summer border at Longwood Gardens. (Photo by Jessie Keith)

    The Oriental Hybrids come into prominence in early August, as the Trumpets fade from the scene.  Their freckled, seductively scented flowers with back-curved petals show the influence of their two primary parents: raspberry-pink-flowered Lilium speciosum and white, yellow-banded Lilium auratum var. platyphyllum. Most Oriental Lilies have nodding or out-facing flowers, but exceptions occur, as evidenced by arguably the most famous lily hybrid, ‘Stargazer’.  The glowing crimson-rose, white-edged blooms of this 1974 introduction look up from 3- to 4-foot stems in early August.  Other outstanding and renowned Orientals include white ‘Casa Blanca’; lilac-pink, lemon-striped ‘Tom Pouce’; white, rose-veined ‘Muscadet’; and white, gold-striped ‘Aubade’.  All are of similar stature to ‘Stargazer’.

    Orienpet Hybrids

    Orienpets tend to be large-flowered and voluptuous. (Image by Jessie Keith)

    Hybrids between Oriental and Trumpet lilies (known as “Orienpets”) combine the best features of both groups, bearing swarms of large, fragrant flowers on lofty stems.  A winner of the North American Lily Society’s popularity poll, the Orienpet ‘Anastasia’ flaunts white, rose-brushed, heavy-textured flowers on 6-foot stems in early August, giving the effect of a high-rise Lilium speciosum.  The cultivar ‘Scheherazade’ sports a similar look, but with raspberry-red, lemon-edged blooms.  ‘Silk Road’ (also known as ‘Friso’) is more suggestive of a Trumpet Lily, producing white, rose-throated, funnel-shaped flowers with burgundy-flushed exteriors in mid-July.  It’s a four-time popularity poll winner.

    Now is the season not only to savor the beauty of late-blooming lilies, but also to order some of their bulbs to plant this fall.  The payoff next summer will be well worth the investment!

  4. Beating Tomato Pests and Diseases

    All winter long, tomato lovers suffer, eating supermarket fruit with the taste and texture of foam packing peanuts.  Finally summer arrives, bringing a harvest of tart, sweet, sunshiny tomatoes.  You can buy these edible jewels at the local farmers’ market, but there is something incredibly satisfying about growing your own.  A just-picked tomato, still warm …

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  5. Garden Plants that Feed Soil Naturally

    Colorful lupines are some of the prettiest garden flowers that add nitrogen to soil.

    Nitrogen is one of the most essential plant nutrients, and one of the best ways to boost nitrogen in your soil is to grow nitrogen “fixing” plants. This amazing group of plants naturally add nitrogen into the soil by taking nitrogen from the air and converting it into a usable form in the soil. And many are common garden plants that you may already grow, like peas, beans, bayberry, or clover.

    Why Grow Nitrogen Fixers?

    Beans and peas are vegetable garden standbys that fix nitrogen. (Image by Jessie Keith)

    Legumes, like beans or peas, are the classic example. Experienced veggie growers know that legumes are the ideal crops to combine or alternate with nitrogen-guzzling gluttons such as tomatoes, corn, or melons. What the cantaloupes take away, the scarlet runner beans restore (at least partially).

    Of course, the legumes work their magic only if their remains remain in the veggie garden.  If you rip out their roots and discard their stems after harvesting your crop, you’ll lose the atmospheric nitrogen that they captured.  The trick is to leave the roots in the ground, and to compost or till in the top growth.  Your garden will reap a significant nitrogen dividend as a result.  Moreover, it’s an ecologically friendly dividend, released gradually as the organically bound nitrogen works its way slowly through the soil’s natural food web.

    How Plants Fix Nitrogen

    Rhizobium root nodules on bean roots. (Image by Dave Whitinger)

    Only a relative few plant species have developed the capacity to split atmospheric nitrogen molecules into individual atoms and to “fix” the freed nitrogen atoms into soilborne compounds that are available to plants. But, these plants don’t do it alone. Nitrogen-fixing plants partner with a narrow range of specially adapted microbes that do the actual splitting and synthesizing of nitrogen.

    When present in the soil, these microbes enter a host plant’s feeder roots, which triggers the formation of round nodules.  The nodules provide a cozy, nutrient-rich environment for the microbes as they set about converting atmospheric nitrogen into a soilborne form that’s available to plant roots.  It’s to this partnership (technically referred to as a symbiotic relationship) that we owe much of our soil fertility, and our food.  Not to mention our flowers.

    Long before biologists teased out the relationship between plants and microbes and nitrogen cycles, farmers already used nitrogen-fixing plants to boost the productivity of their fields.  Although they knew nothing about soil microbes and atmospheric nitrogen, they were well aware that certain plants replenished the soil and enhanced the performance of others crops.

    Astute gardeners still use this principle to bring the best out of their soil.  Got a garden niche that could use a nitrogenous pick-me-up?  Plant a nitrogen-fixer!

    Garden Plants that Fix Nitrogen

    Cover Crops

    Red clover is a great cover crop with colorful flowers that bees love.

    Many vegetable gardeners think big when it comes to nitrogen fixers. They maximize the dividend by using legumes as cover or rotation crops to be mowed and composted rather than harvested.  As a result, the hefty portion (as much as 80 percent) of fixed nitrogen that would have gone to your table will return to the soil instead.  Crimson clover (Trifolium incarnatum), small-seeded fava beans (Vicia faba), and garden peas (Pisum sativum) are among the legumes that make first-rate seasonal cover crops.  Sow them in early spring or late summer, before or after most other crops are in the ground.  Till or compost them at least 4 weeks after the shoots emerge, and at least 3 weeks before sowing another crop onto any tilled areas.  For optimum nitrogen fixation, use seed that’s been inoculated with a compatible nitrogen-fixing bacterium from the genus Rhizobium (available from seed merchants and agricultural suppliers).  These microbes might not be present in your soil, especially if the cover crop is new to your garden.

    Lawn Fixers

    White clover feeds lawns and bees! (Image by Ivar Leidus)

    Lawns also benefit from nitrogen-fixing plants.  Dutch white clover (Trifolium repens) is an excellent case in point.  Time was when most lawn seed mixes contained a quotient of this low-growing, nitrogen-packing legume.  A superior alternative to the humus-depleting fertilizers that are used on all too many lawns, it provides hungry turf grasses with a steady, sustainable, organic source of nitrogen that won’t contaminate neighboring ecosystems with runoff and leaching.  An over-seeding of Trifolium repens in spring or late summer, followed by a light top-dressing of Fafard Premium Topsoil, may be just what your lawn needs if you’re looking to get it off chemical life support.  Dutch white clover’s symbiotic Rhizobium bacterium is present in many areas of the United States, but inoculants are available from lawn and garden suppliers if needed.

    Landscape Fixers

    False indigo is an attractive, nitrogen-fixing perennial. (Image by Jessie Keith)

    Perennial, shrub, and tree plantings can also benefit handsomely from the inclusion of nitrogen-fixers, particularly if your soil is too lean to support prima donna plants.  Outstanding legumes for perennial borders include false indigo (Baptisia spp.), wild senna (Senna spp.), yellow lupine (Thermopsis spp.), lupine (Lupinus spp.), and leadplant (Amorpha spp.).  The roster of leguminous shrubs and trees is also lengthy, boasting such standouts as bush clover (Lespedeza spp.), yellowwood (Cladrastis kentuckea), Kentucky coffee tree (Gymnocladus dioicus), pagoda tree (Styphnolobium japonicum), and Amur maackia (Maackia amurensis).  In addition to adding beauty to the garden, these legumes will improve the performance of neighboring plants by adding nitrogen to the soil.  As with other legumes, inoculation of their seed or the soil with a compatible Rhizobium bacterium may be required for optimum nitrogen fixation.

    Bayberry is a tough shrub that naturally adds nitrogen to soils. (Image by Jessie Keith)

    Equally meritorious are a number of non-leguminous ornamental shrubs and trees that host symbiotic bacteria from the genus Frankia.  These plants, which include bayberry (Morella pensylvanica), New Jersey tea (Ceanothus americanus), sweet fern (Comptonia peregrina), and alders (Alnus spp.), rank among the best plants for improving the soil and beautifying the garden. Many do not require an inoculant, partnering happily with one or more of the Frankia species that naturally occur in soils throughout most of the temperate and tropical latitudes.