As winter deeply settles in this month, gardeners dream about and plan for a new season. Outdoor tasks are pruning and clearing up storm damage. Indoors we are compiling plant orders, working on maps, scanning botanical news, reading and learning, and scheduling garden presentations and activities for spring through fall. Planning for the Friends of the Arboretum spring native plant sale is well underway. FOA is now accepting your advance orders for native plants through February 14.
The native trees and shrubs offered by advance order cover a range of heights and features. In the birch family, paper and river birches (Betula papyrifera and B. nigra, respectively) and American hornbeam or musclewood (Carpinus caroliniana) reach tree size. Each of these trees have attractive fall color and interesting bark—flaking and peeling on the birches, and smooth and ridged on the musclewood. River birch is suited for moist soils, perhaps on the north side of a house or a low lying area. Plant white birch in medium soils, even on slopes. Musclewood can tolerate clay, but grows best in rich soils. It thrives in shade or partial shade, with medium soil moisture. (Some of these may also be available at the tent sale on May 11.)
Downy serviceberry (Amelanchier arborea) is a small tree in the rose family suited to full sun or partial shade, in medium to moist soils. Attractive showy white flowers bloom early in the season, providing a spring resource for pollinators and fruits for animals by late spring. Also in the rose family, American plum (Prunus americana) bears fragrant flowers before leafing out; its fruits ripen late in the summer. Both of these species produce suckers and eventually can form a thicket or hedgerow in an edge habitat.
For small garden spaces, or where a low profile is preferred, New Jersey tea (Ceanothus americanus) and dwarf bush honeysuckle (Diervilla lonicera) are early-summer blooming species. New Jersey tea, a member of the buckthorn family, can be planted in sun or light shade, in dry, rocky, or medium soils. Dwarf bush honeysuckle, in the bush honeysuckle family, grows well in dry partially shaded sites like open woodlands. It produces arching stems by suckers close to the original plant. These species are excellent garden choices and should not be confused with related plants that are known invasives.
FOA is offering several ground covers suited to different light and soil conditions. For full sun, wild strawberry (Fragaria virginiana) and prairie smoke (Geum triflorum) are good choices. These will grow and spread best if they are not overshadowed by other plants. Wild strawberry spreads by runners. Prairie smoke holds its place with dense rosette leaves that persist even when the plant is not in bloom. Both of these species bloom early, in April and May, respectively. For partial shade, Pennsylvania sedge (Carex pensylvanica) will fill in an area with short grass-like plants by rhizome growth. Its tiny flowers are the first to open, usually in April. In fully shaded sites, wild ginger (Asarum canadense) is recommended. It has broad green leaves and can grow with other small woodland plants. Its flowers are open in early spring but are well hidden under the foliage.
Ants disperse the seeds yards away from the original plants. New colonies of wild ginger may establish in other parts of your garden.
Happy gardening new year!
—Susan Carpenter, Arboretum native plant gardener