This is the Garden Column for use during the week beginning Jan. 9.
By Richard Jauron
Iowa State University
In Iowa, the predominant colors of the home landscape in late fall and winter are white and various shades of gray and brown. An excellent way to brighten the drab winter landscape is to plant evergreens (pine, spruce, fir, etc.) and trees and shrubs that possess colorful fruit or bark.
While crabapples (Malus spp.) are usually planted for their flowers, many varieties also possess attractive, persistent fruit. Crabapple varieties with red fruit include ‘Adirondack,’ ‘David,’ ‘Donald Wyman,’ Red Jewel™, and Sugar Tyme®. ‘Indian Magic’ and ‘Professor Sprenger’ have reddish orange fruit, while Harvest Gold® and Golden Raindrops® are yellow-fruited crabapple varieties.
Hawthorns (Crataegus spp.) are another group of small, flowering trees that possess attractive fruit. Hawthorns produce white flowers in spring. In fall, its small (1/4 to 1/2 inch in diameter) fruit turn red and persist into winter. Two hawthorns noted for their excellent fruit displays are the Washington hawthorn (Crataegus phaenopyrum) and ‘Winter King’ hawthorn (Crataegus viridis ‘Winter King’).
The American cranberrybush viburnum (Viburnum trilobum) is an excellent shrub for screens, hedges and mixed shrub borders. The shrub grows eight to 12 feet tall and produces flat-topped clusters of white flowers in spring. Its fruit turn bright red in fall and persist into winter. ‘Hahs’ is a compact variety (grows approximately six to eight feet tall) that produces large, attractive fruit. ‘Wentworth’ grows 10 to 12 feet tall. Its fruit change from yellow-red to bright red in fall.
Most evergreen hollies are not reliably hardy in Iowa. However, several Meserve hybrid hollies (Ilex x meserveae) can be successfully grown in the state. ‘Blue Prince,’ ‘Blue Princess,’ ‘Blue Boy,’ ‘Blue Girl,’ China Boy® and China Girl® have dark, bluish green foliage and are hardy to -10 to -20 F (USDA Hardiness Zone 5). The female varieties produce attractive red fruit. (Hollies are dioecious. Dioecious plant species produce male and female flowers on separate plants. Only female plants produce fruit. However, a male plant is required for pollination and fruit set. Maximum fruit production can be obtained by planting several female plants and one or two males.)
The brightly colored fruit of many of the aforementioned trees and shrubs do not remain throughout the winter. Very cold temperatures in winter eventually cause many of the fruit to turn reddish brown or black. Hungry birds and squirrels may also devour the fruit. However, the fruit display in late fall and early winter can be spectacular.
Selecting trees and shrubs with colorful bark is another way to add interest to the winter landscape.
A widely planted tree that possesses attractive, exfoliating bark is the river birch (Betula nigra). The exfoliating bark varies from salmon white to reddish brown. Often planted as a multi-stemmed specimen or “clump,” the river birch may eventually reach a height of 40 to 50 feet.
Two small ornamental trees with exfoliating bark are the paperbark maple (Acer griseum) and Amur chokecherry (Prunus maackii). The paperbark maple grows 20 to 30 feet tall, possesses cinnamon to reddish brown exfoliating bark and is hardy in USDA Hardiness Zones 5 to 8. The bark characteristics of the Amur chokecherry are highly variable. Bark color varies from brownish yellow to cinnamon brown. Some exhibit little or no bark exfoliation, while others exfoliate heavily. The Amur chokecherry grows 30 to 35 feet tall.
One of the most beautiful sights in winter is the bright red twigs of the redosier dogwood (Cornus sericea) set against a backdrop of newly fallen snow. Native to Iowa, the redosier dogwood grows six to 10 feet tall. Several colorful varieties are available. ‘Cardinal’ has bright, cherry red stems. ‘Alleman’s Compact’ is a compact (grows four to five feet tall), red-stemmed variety. ‘Flaviramea’ has yellow stems.
There are also several varieties of willow that possess colorful bark. The ‘Flame’ willow (Salix ‘Flame’) has reddish orange stems. The stems of the coral bark willow (Salix alba ‘Britzensis’) vary from yellow-orange to orange-red.
The redosier dogwood and willows should be pruned on a frequent basis as the young shoots possess the brightest colors. The ‘Flame’ and coral bark willows should be pruned annually. Cut plants back to near ground level in late winter. The redosier dogwood requires less pruning. In late winter, remove approximately one-third of the oldest stems near ground level.
When selecting trees and shrubs for the home landscape, we often choose plants that have attractive spring flowers or colorful fall foliage. However, don’t forget to include some trees and shrubs that possess colorful fruit or bark in winter.
Laura Sternweis, Extension Communications and External Relations, (515) 294-0775, firstname.lastname@example.org