Native plants can be the backbone or the spotlight in the most formal gardens. New symmetrical gardens in the Dogwood Lawn at the Robert Mills House and Gardens are edged with a cultivar of evergreen inkberry holly, Ilex glabra Gem Box®, surrounding masses of Incrediball® Hydrangea arborescens.
When you decide which trees to plant, you are making the most important decision in landscaping. Trees help restore backyard bird populations by serving as larval food sources. They also shade our yards, help to reduce urban heat zones, sequester carbon, provide leaves for mulch and composting, and intercept and break down the force of raindrops.
In addition, woody foundation plants and plants used for screens and hedges are not only well-suited to traditional landscape design but also serve as extremely important sources of flowers and fruits for pollinators and birds. These offerings are part of an explosive new trend in which plant breeders are creating cultivars, sometimes called nativars, from indigenous plants that fit into even picky homeowner association guidelines. Nativars are a relatively new horticultural tool that directly compete with standard exotics in the landscape, offering all the ecosystem benefits of their species for native animals and insects while still providing the shade, soil stabilization, beautification, and predictability required for urban spaces.
In the old days, a sunny slope ended up planted in what I call “filling station” juniper. Although one commonly used species, J. horizontalis, is native, it still makes a house look like a somewhat soulless commercial enterprise. For a better option, University of Connecticut plant breeder Mark Brand has developed several cultivars of the native black chokeberry. One, Aronia melanocarpa ‘Ground Hog,’ was chosen by Proven Winners as its Landscape Plant of the Year for 2019; it grows 8 to 14 inches by 3 feet, and it is best used as a ground cover as it makes a dense mound when grown in sun to part sun with dry or moist soils. It is being listed as hardy from zones 3 to 9, which puts the Midlands near the bottom end, but Proven Winners does trials across the country, including in Florida and Alabama, to ensure that plants perform as advertised. This one is described as extremely tough and hardy.
Although listed for sun or part sun, choose a slope that has some afternoon shade unless near a pond or such where the surrounding soil has more moisture. And incidentally, if you are plagued by Canada geese, growing plants rather than turf grass near the water’s edge discourages this nuisance wildlife.
This deciduous plant leafs out in spring accompanied by masses of white flowers that attract all sorts of pollinators. In fall, the leaves turn a brilliant red accompanied by a profusion of black fruit that usually last throughout the winter, earning its chokeberry appellation. By the end of winter as other food sources grow scarce, they will be eaten, especially when robins return to town.
Very similar is another black chokeberry cultivar, ‘Low Scape Mound,’ with the same characteristics but with a mature size of up to 2 feet tall and 2 feet wide.
For a hedge that grows up to 5 feet high, consider ‘Low Scape Hedger’ as it is advertised as heat and drought tolerant and would be eye-catching in spring through late autumn. None of these seem to suffer from particular disease or insect pressure.
Foundation plants are perhaps the major focus of most landscapes. Boxwoods, or their look-alikes, have always been the go-to plants for this purpose. But boxwoods have always had numerous problems, leading to both Asian and native holly substitutes that could be used to mimic certain types of the boxwood species and cultivars.
However, new to the fungi in this country, boxwood blight has reached our shores with devastating consequences. Fortunately, plant breeders have greatly expanded the variety of shapes and sizes of native hollies to use as replacements with a huge selection available. A new Ilex vomitoria cultivar Viburnum obovatum ‘Raulston Hardy’ is a tight, densely branched small-leafed shrub that matures at 4 by 5 feet. This is a female clone with insignificant but pollinator attractive flowers that, if you plant a male pollinator nearby, will develop into red fruits. At the other end of the spectrum, I. vomitoria ‘Micron’ has tiny, tightly packed foliage and matures at most 2 feet by 3. With thoughtful pruning (not shearing), it could serve as a substitute for the miniature boxwoods used for parterre borders and such.
From the Ilex glabra breeding programs, ‘Shamrock’ takes sun to part shade and is somewhat loose with dark, glossy foliage attaining 4 or 5 feet in both dimensions. It needs full to part shade, and once established it can be pruned slightly for a tighter look or to allow a more relaxed appearance.
Two plants that, to my eye at least, more closely resemble formal boxwoods are ‘Gem Box’ and ‘Strong Box;’ these are improved cultivars of Ilex glabra, inkberry holly. Although both these cultivars hold their leaves to the ground and require very little if any pruning, ‘Gem Box’ is listed by Proven Winners as being slightly more symmetrically round, attaining a mature 3 feet by 3 feet, and was selected as the 2020 Landscape Shrub of the Year. The Proven Winner site for some reason describes ‘Strong Box’ as having a “tuna can” shape as it is more likely to grow 2 feet tall and 3 feet wide. They looked similar to me, and I was really impressed with their glossy but not too densely packed foliage.
At the Robert Mills House, Curator of Grounds Keith Mearns is implementing a policy, the first in our state, of following our Founding Fathers’ interest in using native plants by installing I. glabra ‘Gem Box’ hollies. Even in the midst of creating a new system of governance, George Washington, Thomas Jefferson, and James Madison were highly focused on gardening, especially with natives. Keith is also replacing the terribly difficult-to-control, ubiquitous liriope border grass with a far better behaved native carex, Carex pennsylvanica.
Although ‘Shamrock’ and ‘Gem Box’ are females and will produce black fruits if a suitable male pollinator is near, gardeners should not discount the importance of the minute flowers, male or female, for any of the I. glabra cultivars. Male flowers produce prodigious amounts of pollen, which is as important to pollinators as nectar from female blossoms. Gallberry, another name for Ilex glabra, honey is highly prized, and beekeepers move hives to natural areas with large numbers of I. glabra plants when they are in flower.
If you have a spot that needs concealing, or need privacy for the outdoor showers I hear are becoming popular, consider some of the new native viburnum offerings. ‘All That Glitters’ and ‘All That Glows,’ both cultivars of V. dentatum, arrowwood viburnum, with maybe some V. bracteatum thrown in, pollinate each other. In addition to their noticeably glossy leaves and showy flat-topped clusters of white flowers around which pollinators gather, you will be rewarded in the fall with deep purple fruit devoured by birds. These plants are a foot different in height, either 5 or 6 feet, but grow fast and should provide plenty of cover. Although deciduous, they are very fully branched individuals that, in addition to providing essential nesting sites for birds, still provide screening after they lose their leaves, which are a glorious palate of blazing fall colors. Both are forgiving of soil types and need average water, and to top it off they’re deer resistant, though not deer proof; remember, hungry deer will eat anything.
A huge debate is underway as to which is better: the straight native species or a cultivar that can be more aesthetically attractive and still fill the needs of the animals that use it as a food or nesting source. If a cultivar is designed to have far more petals as in the case with some coneflowers, they will not produce pollen or nectar. However, some cultivars have heavier flower and fruit sets and improved disease resistance. Overall, I don’t think a homeowner can go wrong with choosing to replace exotic, non-native plants with thoughtfully selected natives.
The plants mentioned in this article are just a drop in the bucket of what is flying out of the breeding programs at nurseries and universities as we address the need for plants tolerant of the changing environmental conditions. This is our opportunity to embrace the native plants that supported indigenous flora and fauna long before we crossed land bridges and stepped off sailing vessels. Bring some wildflowers into your yard through nativar shrubs and enjoy their multifaceted appeal, natural benefit, and beauty.
