Are you seeing signs of spring? After the bold yellow forsythia blooms, purple-flowering trees will soon brighten our yards and hillsides. What are those lovely trees? In March and April in Western North Carolina, these are most likely the native eastern redbud (Cercis canadensis). By late April or May, you’ll see larger purple flowers on the invasive Princess tree (Paulownia tomentosa).
About Redbuds
The eastern redbud is a small deciduous tree—15 to 30 feet tall and 15 to 25 feet wide—native to North America, ranging as far north as Canada, south as Florida, and west to Texas.
The pink to reddish-purple flowers emerge in early spring on old branches and trunks, before the leaves. After blooming, the heart-shaped leaves emerge and mature to a dark green, turning yellow to yellowish orange by fall. The trees produce clusters of green seed pods that look similar to snow peas, but brown when mature.
In the wild, eastern redbud occurs as an understory tree, preferring moist, well-drained soil, but adaptable to a range of soil conditions, and hardy from USDA zones 4 to 9. The trees will tolerate full sun and both alkaline and acidic soils. In WNC, the trees are usually more numerous on south-facing slopes with more sunlight. They are fire-tolerant and will sprout back from the roots after a fire.
Uses
Redbud nectar attracts butterflies and hummingbirds. Pollen feeds honeybees. Birds and squirrels may feed on the seeds. Redbuds are in the pea family—their edible flowers taste like peas, making them a colorful and tasty addition to a spring salad—but only if the trees are untreated with pesticides. Some Native Americans and folk healers use the bark and roots to produce teas and tinctures to treat various ailments.
Diseases and Pests
These beautiful trees are usually free of serious disease and pests, but are relatively short-lived, typically declining from disease after twenty years. The most common culprit is the fungal disease, Botryosphaeria canker, which can encircle the branches, effectively cutting off the water supply to the leaves, leading to branch drop. Keep plants as healthy as possible by watering regularly during dry periods and pruning out diseased branches with disinfected tools. Verticillium wilt, another serious fungal disease, blocks the tree’s vascular system from taking up water and nutrients. Leaf anthracnose and other leaf spot diseases may affect the tree’s appearance but not its overall health.
Insects that feed on redbuds include treehoppers, caterpillars, scales, and leafhoppers. For serious infestations, contact your local Extension office for treatment options.
Cultivars
Eastern redbuds are lovely native trees that are valued in our landscapes. Several redbud varieties are available. Check out some of these selections to see what strikes your fancy.
‘Alba’ (white flowers)
‘Appalachian Red’ (hot pink flowers)
‘Covey’ (dwarf weeping habit)
‘Flame’ (double flowers, seedless)
‘Forest Pansy’ (purple foliage, pink flowers)
‘Ruby Falls’ (purple foliage, weeping habit)
‘Silver Cloud’ (variegated green and white foliage)
‘Hearts of Gold’ (golden foliage)
Avoid the Paulownia!
The Paulownia or Princess tree also blooms in spring with panicles of purple flowers. Paulownia was introduced in the mid-1800s as an ornamental landscape plant. It is now considered an ecological hazard, especially to Linville Gorge and along I-40 near the Tennessee state border. Princess trees are invasive everywhere in our area and are not recommended as landscape plants. Eliminate volunteers before they establish.
Article written by Barbara Hayes, Extension Master GardenerSM Volunteer.
More information
Eastern redbud plant description
by NC State Extension
Eastern Redbud Plant Fact Sheet
by U.S. Department of Agriculture
Paulownia or Princess tree plant description
by NC State Extension
What Are the Purple-Flowered Trees? Paulownia and Oriental Wisteria
by Alison Arnold, Extension Agent, NCSU