Submitted by Jason Reeves
Res. horticulturist, University of Tennessee Gardens, Jackson
I was first introduced to “red-twig” dogwoods by an elderly gardening friend about 25 years ago. She pointed out a large, multi-stemmed shrub growing out in the middle of her lawn called a red-twig dogwood. I had never heard of such and thought to myself “what a strange looking dogwood.”
In the winter of 2011 while driving to Charlottesville, Virginia, Michael Dirr spotted a bright red-twig Cornus amomum growing in a swamp on the side of the highway. Silky dogwood is native along streams, edges of swamps, and other low areas across much of the eastern United States.
Cayenne has fresh green foliage all summer. This shrub dogwod does not produce big showy flowers. Instead, numerous small white flowers looking similar to Queen Anne’s Lace are produced in flat cymes up to two inches wide on the end of the stems in May and June that give way to clusters of pea-size porcelain blue fruit in August and September. The fruits are enjoyed by birds. As the temperature drops the real show begins; leaves turn a striking orange-red before dropping to reveal bright red stems.
Cayenne is a multi-stemmed shrub that spreads by suckers. The best winter stem color occurs on young new growth. Once the stems are a couple of years old, the bark matures to gray. To ensure fresh colorful stems each year, older stems should be cut back close to the ground in late winter or early spring. Strong new stems will quickly spring forth. I like to cut some of the older stems in early December and use them in Christmas decorations both indoors and out. Outside, the cut stems will retain their color all winter long. In early March, I remove the rest of the older stems from the plant.
Hardy in zones 4-9, Cornus amonum ‘Cayenne’ thrives in full-sun to partial-shade and is best grown in good garden soil where supplemental water can be provided in periods of drought. It works well in shrub borders and mass plantings; in moist areas, it can form a dense colony making it great for wetland mitigation. In the garden, if left unpruned, it can reach 6-8 feet tall and 8-10 feet wide in three to five years, depending on moisture.
The UT Gardens includes plant collections located in Knoxville, Crossville and Jackson. Designated as the official botanical garden for the State of Tennessee, the collections are part of the UT Institute of Agriculture. The Gardens are open during all seasons and free to the public. For more information, see the Gardens website: ag.tennessee.edu/utg.