Common Name: Eastern Redbud
Scientific Name: Cercis canadensis
Order: Fabales
Family: Fabaceae
Description Eastern redbuds are small, deciduous shrub trees that have divided trunks near ground level. If they are grown in constant sun, redbuds will be more compact and rounded, but if they are grown in the shade, they will have a looser and more open shape. The crown of a redbud can range from round to flat-topped. Eastern redbud flowers bloom in the spring before leaves appear on the tree. These flowers range in color from pink to reddish purple and occasionally white. They are found on old twigs, branches, and trunks in clusters of two to eight, and each flower contains a pistil and a stamen, so eastern redbuds are therefore self-pollinating with a little help from bumblebees. Mature leaves alternate along the stem and are dark green, heart shaped, and about four inches long and wide. The mature fruit of eastern redbuds are flat reddish-brown pods that are about half an inch wide and two to four inches long. Each of these pods carries four to ten seeds.
Growth Habit Young eastern redbuds germinate above the ground and mature very quickly compared to other plants. If an eastern redbud is planted in the right type of soil, its taproot will grow deep into the ground within a few years. Secondary roots start growing when the taproot is two to three inches long. A seedling in the right growing conditions can grow up to one foot during the first growing season. A developing redbud usually reaches maturity when it is between twenty and thirty feet tall and 15 to 35 feet wide. New leaves start out as a reddish color, turn dark green during the summer, and then turn yellow in the fall before they fall off. Pods containing seeds start off as a light green and change into a reddish-brown color as they mature. These pods remain on the trees after the leaves have fallen off in the fall, and they stay during winter.
Hardiness Zone(s) Eastern redbuds are can be found all the way from New Jersey to Florida to Michigan to Texas and Mexico, so they can survive in a wide variety of temperatures and climates. The January temperatures from regions where eastern redbuds grow can average between 18˚F and 61˚F. The northern most eastern redbuds receive an average of 35 inches of snow. Average July temperatures for the native range of eastern redbuds vary from about 70˚F to 90˚F. Average annual precipitation is between 20 and 50 inches.
Culture The conditions that eastern redbuds can grow in vary a bit. They do best in soil with a pH of 7.5 or higher, but they can grow in a large range of pH and tolerates acidic or alkaline soil. Eastern redbuds prefer well-drained locations with moist soil, but they will grow in pretty much any soil that is not permanently wet, poorly aerated, or coarse sand. Blooms are more numerous on trees grown in sunlight than dense shade, but the trees do prefer a little bit of shade during the summer. Trees become less shade tolerant as they grow older. They will fare better if irrigated during summer dry spells, but they can tolerate moderate ones. Applying mulch and pruning diseased limbs will help keep an eastern redbud healthy.
Diseases & Insects Leaf anthracnose, botryosphaeria canker, and verticillium wilt are the most common diseases that infect eastern redbuds. Botryosphaeria canker is the worst disease in eastern redbuds as it cuts off the water supply to branches and causes stem and leave lesions. Canker has been known to kill entire groves of redbuds since they are especially susceptible to the disease while they are under stress from droughts. Heart rot is common in older eastern redbud trees. Most redbuds will die from some kind of disease before they reach twenty years of age. Insects are also an issue for these trees. Wood borers, redbud leaffolders, grape leaffolders, Japanese weevils, seed beetles, and scales can cause damage to eastern redbuds.
Landscape Value Eastern redbuds are popular ornamentals that are widely grown for their beautiful flowers. They are sometimes used as shrub borders.
References Brakie, Melinda. “Plant fact sheet for eastern redbud (Cercis canadensis)”. USDA-Natural Resources Conservation Service, East Texas Plant Materials Center. Aug. 2010. Web. 19 Apr. 2015.
This document was authored by Alicia Bailey, Department of Agricultural Sciences, Louisiana Tech University, April 2015.