Eastern redbud (Cercis canadensis): what the agencies record

This page reports what US federal publications say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. The family overview, tree species in the agency records, explains the sources and holds the comparison table. Two disease pages cover problems the handbook names for this tree: Verticillium wilt and root and collar rots.

At a glance

Item	What the source records
Scientific name	Cercis canadensis L., legume family (Silvics and PLANTS, symbol CECA4)
Other name, Silvics	Judastree
Native status, USDA PLANTS	Native in Canada and the lower 48 states
Form, Silvics	A small, short-lived deciduous tree; the wood is heavy, hard and close-grained but has no commercial value as lumber because of the small size and irregular shape of the tree
Weight table	Not published for eastern redbud: NRS-38 lists the species only in Table 4, the reference species table, with specific gravities assigned from the average of hardwoods in Table 1A (footnote c), 0.52 for wood on a green volume basis and 0.58 at 12 percent moisture content, and gives no green weight per cubic foot. The Wood Handbook has no row for it

Native range and climate

The Silvics of North America handbook (Agriculture Handbook 654, Volume 2, 1990) gives the range of eastern redbud as New Jersey and southern Pennsylvania northwest to southern Michigan, southwest into southeastern Nebraska, south to central Texas, and east to central Florida. A separate population extends from the Trans-Pecos and south Texas into Mexico. The handbook counts two varieties: Texas redbud (var. texensis), found in southern Oklahoma, Trans-Pecos Texas and southeastern New Mexico, and eastern redbud (var. canadensis) in the rest of the range. It names a second native species, California redbud (Cercis occidentalis), in Utah, Nevada, California and Arizona.

Silvics describes a wide span of climates inside that range. Mean annual precipitation is under 510 mm (20 in) in dry south Texas and about 1,270 mm (50 in) in central Florida, mean January temperatures run from minus 8 degrees C (18 degrees F) to 16 degrees C (61 degrees F), and frost-free days run from 160 to 300.

Soils and forest cover

The handbook says redbud grows on sites from dry to moist but does better on moist, well-drained ones, and is more abundant on south-facing slopes. It does not usually grow on flooded sites because it cannot endure inundation or survive in poorly aerated soils. It is not found in coarse sands and needs some fine or colloidal material. The tree tolerates a wide soil pH range, grows best above pH 7.5, and is prevalent on limestone outcrops and the alkaline soils derived from them. Silvics reports it on soils of most orders, most commonly Alfisols and Mollisols, and says it tolerates nutrient deficiencies. It calls redbud a regular but usually not common part of the understory in many eastern forest types and says it is not listed in all the Society of American Foresters cover types.

Flowers, pods and early growth

Silvics says the flowers are pink to reddish purple, rarely white, borne in clusters of two to eight on old twigs, branches and trunks. They are bisexual and the tree is self-pollinating, usually pollinated by bees. Flowering comes from March to May and before the leaves; in Indiana it needs 30 days of temperatures averaging above 10 degrees C (50 degrees F), and winter chilling also helps. The fruits are flat reddish-brown pods 5 to 10 cm (2 to 4 in) long and 1.3 cm (0.5 in) wide, each holding 4 to 10 hard brown seeds about 6 mm (0.25 in) long. Pods stay on the tree after leaf fall and some last through winter. Many seeds are injured by insects, and the ones that reach the ground usually stay dormant for several years. The handbook says the seed coat does not let water in and the embryo is dormant, which delays germination.

Under good conditions a seedling can grow 0.3 m (1 ft) in its first season, and established seedlings endure much shade. Young trees have been seen flowering for the first time before 7 years old, without fruiting in the first year of bloom. Silvics reports that yearly shoot growth begins during flowering, and that in Indiana saplings started terminal growth when the weekly mean of the daily mean temperature reached 13 degrees C (55 degrees F). It describes a deep taproot that descends fast in the first years if the soil allows, turning sideways where there is an impenetrable subsoil. The handbook says no information was available on vegetative reproduction.

Shade and age

Silvics classes redbud as tolerant of shade, but says it becomes less tolerant as it matures. It says old trees usually suffer from heart rot and cannot normally stand severe competition and shade.

Damaging agents the handbook names

Borers. Silvics lists bark and phloem borers including three Hypothenemus species and Pityophthorus lautus, and a seed beetle, Gibbobruchus mimus, that breeds in the seed. Other wood borers named include Agrilus otiosus, three Micracis species and Ptosima gibbicollis.
Leaf feeders. The redbud leaffolder (Fascista cercerisella), the grape leaffolder, the Japanese weevil and Norape ovina all feed on the leaves.
Sap feeders. The twolined spittlebug, terrapin scale and San Jose scale are recorded on redbud, and the periodical cicada lays eggs in redbud among more than 70 plants.
Diseases. The handbook names three main diseases: leaf anthracnose, Botryosphaeria canker and Verticillium wilt. It calls the canker the most serious, saying one variety of the fungus makes stem and twig lesions and has killed entire groves, and says Verticillium wilt sometimes kills redbuds, especially in the Midwest. Texas root rot is named too, and a variety of sap and heart rots.

Silvics says insect damage is not normally severe and that the tree is not especially vulnerable to insects or diseases. For who takes reports of regulated pests, see reporting a pest in the United States, and pests and diseases by country sets out which ones agencies regulate.

Uses the handbook lists

The handbook calls the tree most valued as an ornamental and extensively planted across the eastern United States, tolerant of a wide range of sites. It records that cardinals, ring-necked pheasants, rose-breasted grosbeaks and bobwhites eat the seed, as do white-tailed deer and gray squirrels, and that the flowers are regarded as important for honey production by bees.