It’s December in Chicago, which means the last leaves have fallen even the last asters are going to seed. The natural landscape is now painted almost entirely in shades of gold, brown and gray.
One remaining pop of color in our native plant pallet is the red twig dogwood (Cornus sericea,also known as the red osier dogwood). As its leaves fall, the stems turn from dull brown to a shining red, making it the star of the winter garden.
Red twig dogwoods belong to a large and diverse genus of plants, which range from medium-sized trees to creeping groundcover. Illinois has several native species of dogwood, including the splendid pagoda dogwood.
The red twig dogwood is native to most of the northern and eastern US, with a range that even stretches across the Rockies to Washington and Oregon. It is a wetland plant, preferring wet to medium soils. At Red Stem, we plant it most commonly in rain gardens, but it is perfectly happy in medium moisture clay soils that dominate the western parts of Chicago and suburbs.
The red twig dogwood is a great foundation plant, ecologically as well as aesthetically. In late spring, it produces white flowers that are visited by a wide range of native bees, butterflies, wasps and flies. Translucent white berries (technically drupes) form in the summer and fall. Their unusually high fat content makes these fruits an important food source for a variety of birds and other animals. Like other dogwoods, the red twig has spectacular fall color, ranging from dark purple to bright red.
While there is little information about why the twigs turn this color, the most common function of red pigment in plants is as a sunscreen, protecting the delicate new branches. The red pigment appears on new growth and gradually darkens to brown as the bark thickens over a few years. Regular pruning is necessary to maintain the attractive shape and winter color of this bush, as well as to manage its size. The best method for this and many other twiggy shrubs is to cut a third of the oldest, gnarliest branches,to the ground late each spring or early winter. This stimulates fresh growth, which is both more aesthetically pleasing and healthier. Pruning this way mimics periodic disturbance from herbivores.
Old and new growth on a mature bush
Unfortunately, the red-twig dogwood is a winter favorite among both rabbits and deer, especially in very snowy years. While a healthy and mature plant can tolerate extensive damage from these hungry mammals, and will re-grow shockingly fast, new plantings can be killed. If you live in an area with lots of rabbits or deer, we recommend protective caging in the first few winters.
Cornus sericea, our native, is one of several similar species that are common in cultivation, prized for their twig color, adaptable nature and manageable size. While we always recommend the straight species, if you are unable to source it, make sure the cultivar you choose is a selection of C. sericea and not one of the many Asian and hybrid cultivars available.
If you have a drier site, gray dogwood (Cornus racemosa) is another of our natives and is similar, though its winter color is not as bright a red. However, this bush suckers very aggressively and we would not recommend it for a small yard unless it is contained.
Written by Liz Olney