Japanese barberry (Berberis thunbergii) and winged euonymus (Euonymus alatus) have been important landscape shrubs and a staple crop for nurseries. The pair are adaptable to different planting locations, including sites that present challenging conditions such as infertile soils, exposure to high winds, heat and reflected sunlight and people pressure. Japanese barberry cultivars are also desired for their vibrantly colored maroon or yellow foliage, compact habit and deer resistance. Winged euonymus is desired for the intense red color the foliage turns in autumn, and a dense, mounded habit.
But sales of Japanese barberry and winged euonymus have declined dramatically in northern regions of the United States because these plants have been found to be invasive. Native plants are a desirable replacement for Japanese barberry and winged euonymus because they are not invasive, and can actually enhance the local ecology by providing habitat for wildlife and support for pollinators.
When looking to replace Japanese barberry and winged euonymus with native species, the ideal plants would be tough, easy to grow, compact and match the maroon or yellow foliage color for Japanese barberry and the red fall color for winged euonymus.
For Japanese barberry, there are very few native shrubs that match the maroon or yellow foliage color of popular cultivars. However, one species that we can look to is Physocarpus opulifolius, commonly known as ninebark. ‘Seward’ Summer Wine is a widely used cultivar that has purple bronze foliage and grows to 5-6 feet tall in cultivated landscapes in full sun. While, Summer Wine has pretty good resistance to powdery mildew, many of the older, large growing cultivars such as ‘Monlo’ Diablo and ‘Dart’s Gold’ (among others) are highly susceptible to the pathogen. In recent years, there has been considerable breeding of ninebark to produce compact, purple or yellow foliage forms that are resistant to powdery mildew. Two new purple cultivars with improved mildew resistance are ‘Donna May’ Little Devil and ‘SMPOTW’ Tiny Wine. Each selection grows 3-4 feet tall.
There is also a new yellow foliage cultivar, ‘Berts Darts G’ Festivus, which stays under 4 feet tall and is reported to have improved mildew resistance. Another possible replacement for yellow leaved barberry is Rhus typhina ‘Bailtiger’ Tiger Eyes, which has attractive, compound leaves that are blazing yellow. In comparison to the straight species, Tiger Eyes is slow growing, and as a result, remains smaller in stature with heights of 3-6 feet in managed landscapes.
Don’t wing it
Compared to barberry, there are many more options for replacing winged euonymus. The obvious requirement for a winged euonymus replacement is that the plant produce red fall color. Low bush and high bush blueberry (Vaccinium angustifolium and V. corymbosum) are often suggested as replacements for winged euonymus because they produce outstanding red fall color on leaves of similar size, shape and texture. However, low bush and high bush blueberry are not as well adapted to tough landscape conditions, because they require acidic soils and even soil moisture during the first couple of years of establishment. One blueberry relative that seems to be demonstrating broader adaptability to landscape conditions is deer berry (Vaccinium staminium). Deer berry is similar to blueberry in flower, fruit (but not as sweet) and most importantly fall color. It’s intermediate in height (3-5 feet) between low bush and high bush blueberries.
Plants of the genus Aronia make a good match for winged euonymus because they produce red fall color and are extremely tolerant of tough landscape conditions. These plants are medium sized shrubs and will eventually reach heights of 5-7 feet. Plants produce numerous clusters of small, white five-petal flowers in spring and showy fruits in late summer into fall. A. arbutifolia (red chokeberry) has red glossy fruits and A. melanocarpa (black chokeberry) has black juicy fruits. Mark Brand at the University of Connecticut has developed a compact form of black chokeberry that offers the same beautiful flowers, black fruits and red fall color but matures at only 2 feet tall.
Another euonymus replacement includes the well-known and widely used red twig dogwood (Cornus stolonifera) offers something ornamental in every season. Plants produce white flower clusters in spring, textural foliage in summer, red foliage color and white fruits in fall, and bright red stems in winter. ‘Kelseyi’ Kelsey’s Dwarf and ‘Fallow’ Arctic Fire stay in the 3-5 feet range. Also in this size range is ‘Bailhalo’ Ivory Halo, which produces variegated green and white foliage, and ‘Neil’ Pucker Up, which produces unique, puckered glossy foliage.
The second is gray dogwood (Cornus racemosa). Gray dogwood is a finer textured plant that tends to have a colonizing habit. Three excellent small growing (2-3 feet) forms include ‘Hurzam’ Huron, ‘Muszam’ Muskingum and ‘Slavinii,’ all of which have reddish fall color. Gray dogwood is noteworthy for ivory fruits and coral red pedicels.
Rhus aromatica ‘Gro-low’ is currently one of the most popular native shrubs, because it’s easy to grow, has a compact (under 1 foot) habit, and excellent orange-red fall color. The plant will establish in a wide range of landscape conditions, and it will even cover the most desolate parking lot islands. During the summer, the glossy, tri-foliate, high quality foliage takes on a unique blue-green color. Amidst the recent celebrity for ‘Gro-low,’ use of the straight species as a replacement for winged euonymus has been largely overlooked. The species boasts the same broad adaptability and orange-red fall color as ‘Gro-low,’ but in a taller (4-6 feet) form. Overall, the straight species is a closer match to winged euonymus than is ‘Gro-low.’
Smooth viburnum (Viburnum nudum var. nudum) offers flat-topped clusters of white flowers and wonderful fall fruits with a kaleidoscope of colors, beginning with porcelain white and transitioning to pink then blue then purple-black. ‘Winterthur’ boasts shiny, deep green foliage. A newer cultivar is ‘Bulk’ Brandywine, which is reported to have a heavy fruit set. Both cultivars stand 5-6 feet tall at maturity in cultivated landscapes.
Sweetbells (Eubotrys racemosa) offers excellent red fall color. In my native shrub trials in parking lots on the University of Connecticut campus, it appears to be fairly adaptable and has shown strong deer resistance. Plant reach 5-6 feet tall in full sun cultivated landscapes and have a habit reminiscent of highbush blueberry.
Another outstanding native shrub, which has had little exposure, is creeping sand cherry (Prunus pumila var. depressa). This plant maintains a low profile (less than 1 foot tall) and is widely adaptable to full sun sites. The long slender foliage is lime green with silver undersides in summer and orange red in fall. Plants produce five-petal, white flowers and small black fruits, typical of other cherry species. Brand’s program has developed a hybrid between P. pumila var. susquehanae and P. pumila var. depressa, two native shrub species whose ranges overlap in New England. The hybrid selection is slightly more upright with larger leaves than var. depressa, and still offers orange-red fall color.
Jessica Lubell is assistant professor, Ornamental Horticulture, Department of Plant Science and Landscape Architecture at the University of Connecticut; email@example.com. Follow Lubell on Facebook at Native Plant Gal for help with native shrub propagation and production, as well as landscape use.
Explore the April 2014 Issue
Check out more from this issue and find you next story to read.
Latest from Nursery Management
- UF/IFAS scientists grow quality caladium varieties
- Longwood Gardens to acquire du Pont estate
- Horticultural Research Institute launches second year of HRI Leadership Academy
- Scapify offers e-commerce solution for growers
- CANERS student scholarship applications now open
- The Peters Company Lean Leader Course launches in February
- Proven Winners ColorChoice Oso Easy Urban Legend rose earns honors at AGRS trials
- Mt. Cuba Center releases new Carex report