Small Native Shrubs for the Garden
In the last 20 years, ornamental shrubs have seen an amazing increase in their popularity. Many genera—including hydrangea, ilex, aronia, itea, clethra, etc.—have experienced an amazing renaissance in the home garden. In March, I gave a webinar talk to the American Hydrangea Society with more than 200 people registered to specifically hear about hydrangeas.
For many shrubs, hydrangeas included, they can get very large and robust over time, making them difficult to incorporate in the garden, especially for those with a small space, a courtyard garden or perhaps a small urban garden. Fortunately, because of the popularity of shrubs, many of the companies who have active shrub breeding and selection programs are continually seeking shrubs that are more diminutive in stature to serve the gardener with limited space.
My recent lecture was on “Designing with Hydrangeas,” and while many can have a very large stature, there are some great smaller selections. The oakleaf hydrangea, Hydrangea quercifolia, has stunning cones of white flowers in mid-summer followed by wine red fall color. This species is an understory native throughout many of the southeastern states.
Both Pee Wee and Sike’s Dwarf each reach 3-ft. tall with an equal spread, and more diminutive leaves and flowers. Little Honey is a selection with striking butter-yellow leaves throughout the entire growing season and is perfect to brighten a shady spot in the garden. For the best foliage color, plant it in dappled shade or on the edge of a wooded area. Too much sun will result in faded leaves, and conversely, too much shade will cause the foliage to turn green.
From the United States National Arboretum breeding program, Ruby Slippers is slightly larger in stature and has a profusion of white panicles of flowers in the summer that fade to a stunning deep burgundy-pink.
Throughout the native woods of the northeast, Midwest and the Southeast, the smooth hydrangea, Hydrangea arborescens, can be found. As an understory plant, it’s an interesting flowering shrub with white, mound-like flowers in the summer. In the garden, the smooth hydrangea can be one of the most stunning of all the shrubs. Hydrangea arborescens Annabelle is perhaps one of the most popular and iconic of all the hydrangeas. It’s hardy in most states throughout the U.S.
I’ve seen amazingly beautiful plantings in Atlanta, Chicago and Philadelphia alike. Annabelle has large, white, mophead flowers in mid-summer that fade to lime green and ultimately a tawny color for fall and winter interest. Plants that aren’t cut back can get quite large. However, Tom Ranney’s breeding program at North Carolina State University near Asheville has paved the way for many new introductions through the trademarked Invincibelle series.
The first breakthrough was to essentially develop a “pink Annabelle.” Hydrangea Invincibelle Spirit was just that and since then there have been many more introductions, including several that are perfect for the small garden. Hydrangea arborescens Limetta and Wee White are both small versions of Annabelle, and Mini Mauvette is a diminutive form of Invincibelle Spirit with a compact habit and an abundance of pink globe-like flowers.
Virginia sweetspire, Itea virginica, is one of my all-time favorite shrubs. This USDA Zone 6 to 9 shrub grows by underground stems, making it perfect for massing in the garden. It’ll grow in both dry and very wet soils. It flowers best in full sun and many of the cultivars can have stunning, deep purple-red fall color. And in late spring to early summer, depending on where you live, an abundance of white, bottlebrush-like flowers with a beautifully sweet fragrance are produced. The most popular selection remains Henry’s Garnet, which can reach up to 5-ft. tall. Little Henry only reaches 3-ft. tall and wide.
Another great shrub for bottlebrush-like flowers and summer fragrance is the aptly named summer sweet, Clethra alnifolia. Recently, I was in the New Jersey Pine Barrens where clethra is one of the most abundant of all the understory shrubs. This colonizing shrub can grow in a variety of conditions and soils, including very wet conditions and even in standing water. In late summer, the generally white flowers have an amazing, perfume-like scent. In the fall, the leaves turn stunning shades of yellow and gold. For the small garden, the staple for years has been Hummingbird, which can be used as a massing low shrub and even be used as a medium-sized groundcover, making it a great plant for stabilizing slopes and banks. This past summer, I was visiting Pleasant Run Nursery in New Jersey and I saw a very large mass of Tom’s Compact, which will reach 4-ft. tall with a very dense habit.
Pictured: Tom’s Compact summer sweet offers up a dense habit and 4-ft. tall growth. Photo Credit: Lisa Strovinsky, Pleasant Run Nursery.
Another native shrub that continues to grow in popularity is Aronia melanocarpa, black chokeberry. The trademarked Low Scape Mound is a small stature selection, which is highlighted by multiple seasons of interest. This small hardy shrub has an abundance of delicate pure white flowers in the spring. In the fall, the foliage can turn a fire engine red and the abundance of plump berries turn a deep purple-black. The fruits are popular with myriad of birds.
An entire article could be written on hollies—a recent breakthrough is with the introduction of an inkberry holly, Ilex glabra Strongbox, which is being promoted as a potential replacement hedging plant for the boxwoods that are suffering from boxwood blight in many parts of the country.
Andrew Bunting is the Vice President of Public Horticulture for the Pennsylvania Horticultural Society, which uses horticulture to advance the health and well-being of the Greater Philadelphia region. Andrew has decades of horticultural experience, ranging from his tenures at public gardens in the U. S. and abroad, as well as a published author, gardening expert and sought-after presenter. To learn more about PHS or to become a member and support greening initiatives in over 250 neighborhoods, visit PHSonline.org.