Evergreens for Screening and Privacy
by Betsy Washington
Recently I have been asked to recommend some shade tolerant evergreen plants for screening that will not grow too tall. Late fall is the perfect time to assess your garden with a critical eye in terms of structure, privacy, and winter interest. Do you have an unsightly view that could benefit from some evergreen screening? Does your garden have enough color and evergreen foliage now that the leaves have dropped? Perhaps a beautiful holly loaded with red fruit would enliven your garden through the winter months while hiding the view of your neighbor’s woodpile. Or imagine an informal hedge of camellias with their glossy evergreen foliage and sumptuous blooms for months in fall and early winter. Check out some of these lovely evergreens and be ready to plant a few of these beauties next spring.
Our native American Hollies are magnificent and quite shade tolerant, with handsome spiny foliage and prolific red berries. They are moderately slow growing which makes them well suited for small gardens’ however a couple of cultivars stand out for their vigorous growth. ‘Merry Christmas’ and ‘Satyr Hill’ are award winning cultivars that grow quickly and vigorously and fruit heavily even when young. Both will eventually reach 25 or 30’ in height but can be maintained at a smaller size with annual pruning. In fact, American hollies can be sheared into a formal hedge only 10 – 12’ high, as seen in several estates along Foxhall Road in D.C. If pruning is too much trouble, choose a slow growing, small cultivar like ‘Vera’ or ‘William Paca’. If American Hollies grow taller than you want, consider trying one of the new Red Hollies, that range in height from 10 – 15’, They all feature spiny, glossy red new growth and abundant red fruit – all in a small package perfect for foundations or a small garden. Cultivars include: ‘Cardinal’, ‘Oakleaf’,’Festive’, ‘Robin’, and ‘Little Red’.
Hollies are dioecious meaning that female and male flowers occur on separate plants. For good berry production, be sure a male is growing nearby. You can read about many more outstanding hollies at www.finegardening.com/plants/articles/evergreen-hollies.aspx
I am particularly fond of the beautiful Tea Oil Camellia, C. oleifera, which is hardier than most camellias, surviving temperatures as low as - 9 degrees. The Tea Oil Camellia is quite vigorous and can reach 12 – 15’ in height and width and glossy dark green leaves and stunning cinnamon colored bark. It blooms for several months through fall, often continuing into December of January, and of often completely covered with single white flowers. Dr. Ackermann of the National Arboretum crossed the hardy Tea Oil Camellia with more tender camellias and has introduced a number of hardy hybrids that are well suited for our area. ‘Winter Star’ is a vigorous hybrid with large, pink flowers in early fall, ‘Snow Flurry’ has double white flowers and a spreading habit, and ‘Winter Interlude’ has an upright habit and soft pink-lavender flowers. All are available at local garden centers. Camellias prefer moisture retentive, acidic soils with excellent drainage. This is best accomplished by planting on a slope and adding copious amounts of compost, leaf mold, or even pine bark. Asian Valley at the National Arboretum boasts the best collection of hardy camellias in the area along with the stunning Camellia oleifera, known as ‘Lu Shan Snow’. Green Spring Park also has an excellent collection. Learn more about these lovely evergreens at: www.usna.usda.gov/Gardens/faqs/Camellia.html
Many gardens in Lake Barcroft flaunt massive old rhododendrons that are covered in voluptuous trusses of flowers in May and June. If you are willing to loosen and amend our ubiquitous clay soil with pine bark and compost, there are several species and cultivars that do well here. The native Rosebay Rhododendron, Rhododendron maximum, grows up to 15’ high or more. Hundreds of these majestic shrubs completely cover steep hillsides above streams in our mountains and create a sensation when they bloom in mid June. Another excellent species hails from Asia. Fortune’s Rhododendron, R. fortunei, has handsome, paddle shaped leaves and large trusses of surprisingly fragrant, lavender flowers in May. Large old shrubs can be seen under the tall oaks in the Dogwood Collection at the National Arboretum. Fortune’s Rhododendron is the parent of a group of outstanding hybrids often referred to as the Dexter hybrid rhododendrons after their breeder. ‘Caroline’, ‘Janet Blair’, and ‘Scintillation’ are are among the best rhododendrons for our area and are resistant to phythopthera root rot which can plague rhododendrons grown in heavy clay soils. Rhododendrons need afternoon shade and moisture retentive but well drained, acidic soils. The American Rhododendron Society website, Potomac Chapter, has excellent photos and more recommendations for rhododendrons that perform well in our area at: www.arspvc.org
If amending your heavy clay soils sounds like too much trouble and you just want a quick, bullet-proof , evergreen screen, try one of the cherry laurels. The upright Skip Laurels, although not as dazzling as hollies, camellias, and rhododendrons, are tough and adaptable. They grow quickly, have lustrous dark green foliage and tolerate shade and heavy clay soils. There are two forms available in the trade, but the “west coast” form with serrate leaves, grows much faster and can reach 5’ or more in just a few years. The Leatherleaf Viburnum is another tough shrub that needs some shade to do its best. It has large, corrugated, dark green leaves and can reach 10 – 15’ in height and width in a few years time. It flaunts large creamy white flowers in May which then ripen into red and then black fruit in fall. It‘s bold foliage makes it a perfect backdrop for fine textured plants like azaleas in a shady garden.