Extension Educator, Horticulture
Some plants seem to take a long time to reach any popularity even though they possess unique characteristics. Bad publicists I guess. A few pictures in the right magazines can launch a shrub's popularity and demand. And since I get so many questions about shade plants, I thought this article about some lesser known shrubs was worth repeating.
Unique attributes of these shrubs are their shade tolerance and interesting flowers, a combination not often seen in shrubs. Although they are all adaptable to a variety of sites, they would prefer moist, acidic and well drained soils. However, they are not nearly as finicky as rhododendrons or blueberries. A soil test, adding sulfur if necessary, adding compost, using fertilizers for acid-loving plants, and watering during drought periods will help all of these shrubs to thrive.
Summersweet Clethra, Clethra alnifolia, is an excellent shrub for year around interest offering fragrant flowers, attractive leaves and interesting form. Its upright growth reaching 3-8 feet tall makes it appropriate for narrow spaces such as next to home foundations or in perennial borders. Summersweet's finest attributes are its shade tolerance and its late season fragrant flowers. The flowers of white, pink or rose appear when few other plants are blooming in July and August. It has few insect and disease problems but thrives best in moist acidic soils.
Some of Summersweet Clethra's notable cultivars (cultivated varieties) include 'Hummingbird' with its 3-4 feet tall low mound and abundantly produced white flowers and 'Rosea' with its glossy leaves and pink flowers later in the season. Its blooming period may last as long as 2 months.
Bottlebrush buckeye, Aesculus parviflora, also offers summer flowers and prefers shady locations. It makes an excellent specimen plant or as a massed planting. Bottlebrush buckeye is native to Georgia and Alabama. Its spreading multistems reach 9-12 feet high and 15 feet wide and give it an interesting winter form. Bottlebrush buckeye has flowers resembling its name with large white panicles 8-12 inches long and four inches wide in July and August.
Spicebush, Lindera benzoin, is another native shrub with interesting flowers. Although the greenish yellow flowers are much smaller than the buckeyes, they appear in April before the leaves and may last for 3-4 weeks. Spicebush will grow in deep shade, but its best flowering and fall color occur when it has some sun. The scarlet fruit ripening in August through October is attractive to birds. For best fruiting, a male and female shrub are necessary. The stems are spicely aromatic and were once used to make a tea.
Witch Alder, Fothergilla gardenii, is a slow-growing shrub only reaching 2-3 feet tall with a compact mounded habit. Another shrub with year around appeal, fothergilla has fragrant flowers of cream colored bottlebrushes in spring before the leaves. It has magnificent fall color of yellow, orange and crimson and will grow in sun or shade. Fothergilla works in nicely with rhododendrons or as a foundation plant. 'Blue Mist' is a very attractive cultivar with blue green leaves.
Some other wall flower shrubs for shady spots include:
Lesser known shrubs may require some extra effort in locating sources, but many garden centers will make special orders if you ask now.
Don't forget the Champaign County Master Gardeners Garden Walk on June 12. Tickets are available at the Idea Garden and most local garden centers.