“Hi, I am desperately trying to find mini shrubs to fill in a long planter box in my backyard. I have two boxes in full sun and looking for an arrangement that looks great all year around. So, I think I need small shrubs (max 2 feet tall) mixed in with flowers, but I have no idea where to start, what looks good together. I did see Purple Pixie Weeping Loropetalum on a Home Depot website, but it seems like it would die. Any suggestions, articles, places I can look at arrangements would be greatly appreciated.” Question from Andrea of Brooklyn, New York
Answer: There are lots of dwarf shrubs suitable for container culture that are hardy to your USDA Hardiness Zone 6 location. You are correct about the Loropetalum. It is hardy to Zone 7, so it will not tolerate the cold where you live. Here are some very compact, evergreen options that would look pretty in your containers year-round and survive in your planter boxes. All will grow best with well-drained containers filled with a top-quality mix, like Fafard® Ultra Outdoor Planting Mix.
Compact, Hardy Shrubs for Containers
Tater Tot® Arborvitae reaches 12-24 inches and has the cutest, tidiest mound of evergreen foliage.
Jelly Bean® Blueberry stays small, looks like a tiny boxwood, and has the benefit of edible berries and colorful fall leaves.
Lil’ Ditty® Witherod Viburnum is tiny and has clusters of white flowers in spring, attractive foliage, and fall/winter berries.
Don’t have as much space for growing vegetables? Then maybe it’s time to go the way of Jack with his beanstalk. Numerous veggies are vines perfectly suited for training up a trellis, thereby taking advantage of upright, aerial space. Vertical veggies also hold their fruits clear of the ground, reducing their susceptibility to rot. Three-dimensional gardening offers multiple advantages.
There are a couple of common trellis types. Crosswise bamboo trellises fitted with trellis netting is an easy way to go. Twine strung between sturdy stakes or posts provides an excellent trellis for most vertical vegetables. Run a horizontal length of twine along one side of the plant row, then loop it back on the other side to secure the stems. Add a new tier of twine every 8 to 12 inches or so to keep pace with the vines. Alternatively, you can secure your climbers with twist ties or snippets of string. Some veggies help by self-attaching with “grasping” structures such as tendrils.
I featured three climbing veggies – Malabar spinach, scarlet runner beans, and purple pole beans – in last month’s “Easy, Attractive Vegetables for Any Garden”. Now we’ll go further.
String or snap beans (Phaseolus vulgaris) are undoubtedly the aerial champions of the veggie tribe. The ever-popular snap (or string) bean comes in a variety of twining forms, including the purple-fruited varieties profiled in last month’s article. All are wonderful for threading through a twine trellis, or for growing up a teepee of tall stakes. They include:
Standard-issue green beans. Heirloom favorites ‘Blue Lake’ and ‘Kentucky Wonder’ both are available as climbers (many gardeners favor them over the bushy versions because they are more productive). More recent introductions include ‘Fortex’, featuring long slender pods that ripen relatively early, and somewhat shorter-podded ‘Malibu’.
Speckled beans. The tan, purple-streaked pods of the heat-tolerant variety ‘Rattlesnake’ are borne most prolifically in areas with long growing seasons, making it a great choice for Mid-Atlantic and Southeast gardens. Speckled varieties for cooler climates include ‘Cascade Giant’, a prolific producer of large beans that are similar in coloration to ‘Rattlesnake’.
Flat, Romano beans. Among the best romano varieties for cooler climates is ‘Northeaster’, with tender 7-inch beans that ripen some 55 days after sowing. For a later, longer harvest, try ‘Helda’, which produces tasty 9-inch pods for much of the summer.
Yellow wax beans. The 5-inch pods of ‘Grandma Nellies Yellow Mushroom’ have a wonderful rich complex flavor that really does have hints of chantarelle. Many of the best wax pole beans are also golden romano types. These include ‘Goldmarie’ and the Italian heirloom ‘Marvel of Venice’, which also has pinkish-purple flowers.
Shelling beans. Grown for their colorful and flavorful seeds that are shucked from the pods late in the season, these varieties are sometimes also excellent as snap beans. One such variety is the heirloom ‘Cherokee Trail of Tears’, whose tasty pods yield shiny black seeds if left on the vine. Another excellent multi-purpose American Indian heirloom variety is the white-seeded ‘Hidatsa Shield Figure’, named for the seeds’ oblong tan markings.
Lima beans or butter beans (Phaseolus lunatus) are grown for their broad, flattened, buttery seeds, lima beans are a much more diverse tribe than the frozen food section of your local supermarket might lead you to believe. The heirloom ‘Willow Leaf’ bears small, meltingly succulent, greenish-white limas, borne on disease-resistant vines furnished with distinctive narrow foliage. A favorite of Thomas Jefferson, ‘Sieva’ also produces small whitish scrumptious limas, but on high-climbing vines with broad leaves. Some Phaseolus lunatus varieties are brightly colored, as is the case with the heirloom ‘Christmas’. It yields large, white, heavily red-splotched limas on tall disease- and heat-resistant vines.
Yardlong beans (Vigna unguiculata) are East Asian legumes grown for their remarkably long slender beans that ripen all summer on tall, vigorous, exceptionally heat-tolerant vines. Look for ‘Chinese Red Noodle’, with deep red, 18-inch beans; ‘Chinese Mosaic’, with pale purple pods; and ‘Taiwan Black’, which produces 40-inch-long fruits studded with black seeds.
Other Vigna unguiculata varieties are grown expressly for their seeds, commonly called cowpeas, rather than their pods. Many of these varieties also grow as vines, including ‘Whippoorwill White’, ‘Blue Goose’, and another Thomas Jefferson favorite, ‘California Blackeye’. All varieties of the species do best in areas with hot summers and long growing seasons.
Many shelling, snap, or snow pea (Pisum sativus) varieties produce long stems furnished with clasping tendrils to hold them upright. They grow best in spring, fall, or areas with cooler summers, so keep this in mind before planting them. The tallest varieties such as ‘Tall Telephone Pole’ will top out at 6 feet or more. Some peas grow as low bushy plants, so be sure to check before purchasing. (Click here to learn more about growing peas.)
Tomatoes (Solanum lysopersicum) are often described as growing “on the vine”, and many of them do exhibit clambering, vine-like growth. Yet relatively few gardeners treat them that way. To trellis your tomatoes, start with an “indeterminate” variety – the term for types that keep lengthening their stems rather than growing to a certain height and stopping. Train the plant’s main stem up a sturdy twine trellis as described above, pinching out any side suckers that appear. Rampant varieties such as ‘Yellow Oxheart’, ‘Black Cherry’, and ‘Climbing Triple Crop’ will ascend to 10 feet or more. You can also allow your tomato vines to double back down the trellis once they’ve reached the top. Avoid determinate varieties, which will resolutely not climb. (Click here to learn more about growing cherry tomatoes.)
Cukes (Curcumis sativus) are natural-born climbers, equipped with curlicue tendrils that cling to whatever structure they’re scaling. Consequently, they’re a natural choice for training up a sturdy trellis or fence. Less weighty types such as pickling cukes are often the best choice. A few varieties such as ‘Japanese Climbing’ have been bred expressly to grow as vines. Of course, you’ll want to avoid bush cucumbers, which are bred not to climb. The small-fruited, heat-tolerant Beit-Alpha type cucumbers are also recommended. The easy, crisp, and delicious ‘Diva‘ is a good one to start with. (Click here to learn more about growing cucumbers.)
Cantaloupes (Curcumis melo), watermelons (Citrullus lanatus), and many other melons have vining habits and work well as climbers. The average cantaloupe or small-fruited watermelon (such as ‘Sugar Baby’) will require something much sturdier than a stake-and-twine trellis. Four-by-four posts and heavy-gauge wire are more like it. (Click here to learn more about growing melons.)
Bottle and swan gourds (Lagenaria siceraria), luffa (Luffaaegyptiaca), and a number of other gourd species grow on rampant vines that benefit from the support of a sturdy trellis or other structure. With their fanciful shapes and colors, gourds are a kick to grow, and kids of all ages love them. Favorites include ‘Bird House‘, ‘Big Apple’, ‘Bushel Basket’, and Luffa for homegrown skincare.
There are lots of reasons to grow shrubs in containers. You may have a small garden or no garden at all. The only sunny spot on your property may be covered with concrete, or your soil may be so poor that even poison ivy fails to thrive. Then again, your “garden” space may be a porch, terrace or balcony. Perhaps you have acres of space but want distinctive potted garden accents. Whatever the reason, container gardening is in vogue, with the selection of beautiful, small shrubs and landscape pots at an all-time high.
Why Compact Shrubs?
Breeders are riding the container-gardening trend, producing compact versions of many of the most popular shrubs. But, don’t assume that words like “compact”, “miniature” or “dwarf” are synonymous with a “manageable size.” The compact version of an 8-foot shrub may still be 5 feet tall—too big for many containers. Always check plant tags and reference sources for the mature size of any plant before purchase.
Most small shrubs can flourish in containers that are between 18 and 24 inches wide and equally deep. If you live in a cold-weather climate, and the containers are going to stay out all winter, avoid thin ceramic or terra cotta pots, which will crack in very cold weather. Heavy, high-fired, glazed ceramic pots as well as metal, plastic, and resin containers won’t crack. (Click here to learn more about the best containers to overwinter outdoors.)
So, commit to container-grown shrubs. Pick your favorite shrub species, and do a little research to find small varieties. Attention to cultural requirements—sun or shade, drought-tolerant or moisture-loving—will prepare you to enter the universe of compact shrubs for containers. The following are a few of the better shrub options for the task.
Compact Evergreen Shrubs
For lovely rounded shape, it is hard to beat Anna’s Magic Ball arborvitae (Thuja occidentalis Anna’s Magic Ball®, USDA Hardiness Zones 3-7, 10-15 inches). Thriving in sunny spots, the Proven Winners’ plant boasts soft, almost ferny evergreen foliage that holds its color through the winter. At maturity, it tops out at around a foot tall and wide. Another rounded specimen, Wee Willie Korean boxwood (Buxus sinica var. insularis Wee Willie®, Zones 5-9, 2 feet tall and wide), has all the boxwood virtues—neat rounded appearance and fine green leaves, plus manageable dimensions. A pair of potted Korean boxwoods look wonderful framing an sunny or partially sunny entrance. For something a little less formal and a little bluer, try the sun-loving Blue Star juniper (Juniperus squamata ‘Blue Star’, Zones 4-8, 2-3 feet tall by 3-4 feet wide). Another sun lover, it has textural foliage of dusty blue-green.
Cavatine andromeda(Pieris japonica ‘Cavatine’, Zones 5-8, 2-3 feet tall and wide) combines small size with a floriferous habit and evergreen nature. The prolific spring bloomer covers itself with honey-scented bells and performs well in light shade.
Compact Shrubs Full of Flowers
Flowering shrubs grown in containers give great garden value, and it’s easy to find old favorites in smaller sizes. Rhododendron lovers can rejoice in Ginny Gee rhododendron(Rhododendron ‘Ginny Gee’, Zones 5-8, 1-2 feet tall and wide), a pink-and-white flowered beauty perfect for containers. The leaves are dark green and small, and the habit is dense. Like most rhodies, ‘Ginnie Gee’ flourishes in light shade.
Hydrangea breeders have extended the range of offerings of this popular shrub and one of the best is Invincibelle® Wee White hydrangea(Hydrangea arborescens Invincibelle® Wee White, Zones 3-9, 1-2.5 feet tall and wide ). This early summer bloomer pumps out pink, globe-shaped flowerheads that age to white. Unlike older hydrangea varieties, Invincibelle® Wee White also flowers on new woods, so blooms appear throughout the growing season. Give it full sun to partial shade, good potting soil, and regular moisture.
There are plenty of little butterfly bushes (Buddleia hybrids) to attract all kinds of garden pollinators, whether the shrubs are in-ground or in containers. Lo & Behold®Blue Chip Jr. butterfly bush(Buddleia Lo & Behold® Blue Chip Jr., Zones 5-9, 1.5-2.5 feet tall and wide ) features deep blue-purple flowers that bloom in mid-summer and beyond. All Junior requires is a sunny spot and don’t self-sow prolifically, like standard buddleia.
Container gardeners can also cultivate wonderful rose gardens full of color and scent. Patio roses boast all the winning qualities of their larger relatives in smaller packages. Some of the newest and best are all of the colorful, compact landscape roses in the Oso Easy ® Series. The double-pink-flowered Oso Easy®Strawberry Crush (Zones 4-9, 2-3 feet ) andyellow-double-flowered Oso Easy®Lemon Zest (Zones 4-9, 2-3 feet) are both effortlessly beautiful high performers.
Or you could consider an English patio rose. The rose-red, repeat flowering Sophy’s Rose (Zones 5-11, 4 feet) is the largest size one would consider for a container rose. James L. Austin (Zones 5-11, 4 feet), with its large, fully double flowers of fuchsia pink, is another good choice. Those wanting a less demanding color should consider the highly fragrant, palest yellow, double rose Vanessa Bell(Zones 5-11, 3 feet).
Colorful Leaves for Extended Interest
Container-grown shrubs, like their in-ground relations, can be the workhorses of the garden, providing interest in multiple seasons. The leaves of the southern favorite dwarf variegated aucuba(Aucuba japonica ‘Variegata Nana’, Zones 6-10, 4 feet tall and 2-4 feet wide) are dark green splashed with gold, lighting up the garden. This shrub is best in a large pot placed in partial shade to full sun.
Lil Miss Sunshine® Bluebeard (Caryopteris x clandonensis L’il Miss Sunshine, Zones 5-9, 2-3 feet) is a stunner, sporting golden-green leaves and azure blue flowers in late summer. Grown in full sun, this sunshiny plant will provide interest throughout the growing season.
Compact fruit-bearing shrubs are also gaining momentum, and the little blackberries, blueberries, and raspberries in the Bushel and Berry® series have quite a following. One to try isBushel and Berry® Peach Sorbet blueberry (Vaccinium Bushel and Berry® Peach Sorbet, Zones 5-10, 1.5 feet tall and 2 feet wide ). The leaves attract attention, ripening from peachy-pink to green and eventually turning red in the fall. Bell-shaped white flowers appear in spring, followed by blueberries in early summer. Supply full to partial sun, fertile acidic soil, regular water, fertilize and blueberry harvests are guaranteed.
Raspberry lovers can rejoice in Bushel and Berry®Raspberry Shortcake® (Rubus Raspberry Shortcake®, Zones 4-9, 2-3 feet tall and wide). Single, white, spring flowers give way to big red raspberries. The canes are also thornless, which will please raspberry pickers. Like most other fruiting plants, Raspberry Shortcake ® produces best in full sun.
A Few Words About Culture
Success with shrubs in containers starts with the right pot. Make sure it is three times wider than the plant’s root ball and contains drainage holes at the bottom and a saucer to catch water. When you have matched a shrub to a container, fill the container with a quality potting mix, like Fafard® Ultra Container Mix with Extended Feed that feeds plants for up to 6 months. The addition of a continuous-release fertilizer will help plants grow their best.
At planting time, make sure the plant’s roots are not pot bound and intertwined when you remove it from the container. If they are, gently loosen them. Make sure the final soil level is 2 inches below the rim of the container, and firm the soil around the new shrub, making sure there are no air pockets. The top space will allow plenty of room for water. Water thoroughly until it percolates through to the bottom of the container. Potted plants require more water than those grown in-ground, and that often means daily watering while the plant establishes roots, as well as in dry seasons. In general, water when the top three inches of soil feel dry to the touch.