Introduction
'Oklahoma' redbud is a deciduous tree, native to southwestern North America including Texas, that reaches 30- to 40-feet in height with a 15- to 20-foot width, and grows slowly into a rounded or vase shape. Young trees are a bit irregularly shaped and benefit from some training and pruning to form an upright, more uniform crown. The incredibly shiny, thick, leathery, dark green leaves have rounded or notched tips, are 2 to 3 inches wide, and turn yellow before dropping in the fall. The deep pink to red flowers appear in profusion up and down the tree limbs in springtime, well before the leaves begin to emerge, creating probably the best redbud display. The 4-inch-long seedpods that follow are a lovely purple color and remain on the tree well into the winter.
Credit: Ed Gilman, UF/IFAS
General Information
Scientific name: Cercis reniformis
Pronunciation: SER-sis renn-ih-FOR-miss
Common name(s): Oklahoma redbud
Family: Leguminosae
USDA hardiness zones: 6B through 9A (Fig. 2)
Origin: native to North America
Invasive potential: little invasive potential
Uses: street without sidewalk; sidewalk cutout (tree pit); deck or patio; shade; specimen; reclamation; highway median; tree lawn > 6 ft wide; tree lawn 4–6 feet wide; tree lawn 3–4 feet wide; parking lot island > 200 sq ft; parking lot island 100–200 sq ft; parking lot island < 100 sq ft; container or planter
Availability: somewhat available, may have to go out of the region to find the tree
Description
Height: 20 to 25 feet
Spread: 15 to 20 feet
Crown uniformity: irregular
Crown shape: round, vase
Crown density: moderate
Growth rate: fast
Texture: coarse
Foliage
Leaf arrangement: alternate (Fig. 3)
Leaf type: simple
Leaf margin: entire
Leaf shape: orbiculate, ovate, cordate
Leaf venation: palmate
Leaf type and persistence: deciduous
Leaf blade length: 2 to 4 inches
Leaf color: green
Fall color: yellow
Fall characteristic: showy
Flower
Flower color: pink, purple, lavender
Flower characteristics: very showy
Fruit
Fruit shape: elongated, pod or pod-like
Fruit length: 1 to 3 inches
Fruit covering: dry or hard
Fruit color: purple
Fruit characteristics: attracts birds; showy; fruit/leaves not a litter problem
Trunk and Branches
Trunk/bark/branches: branches droop; not showy; can be trained to one trunk; thorns
Pruning requirement: needed for strong structure
Breakage: susceptible to breakage
Current year twig color: brown
Current year twig thickness: medium
Wood specific gravity: unknown
Culture
Light requirement: full sun, partial sun or partial shade
Soil tolerances: clay; sand; loam; acidic; alkaline; well-drained
Drought tolerance: high
Aerosol salt tolerance: none
Other
Roots: not a problem
Winter interest: no
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: susceptible
Pest resistance: resistant to pests/diseases
Use and Management
The tree usually branches low on the trunk and if left intact forms a graceful multi-trunked habit. Be sure to avoid weak forks by pruning to reduce the size of lateral branches and saving those that form a U-shaped crotch, not a V. Keep them less than half the diameter of the main trunk to increase the longevity of the tree. This will reduce branch splitting. The low branching habit makes redbud ideal for use as a specimen, deck, or patio tree, and it is especially suited for planting on 15-foot centers on both sides of an entry walk or long entrance driveway. Unfortunately, disease often shortens its life, but the tree puts on quite a show for a couple of decades, and it is well worth the effort to have to replant at this time.
'Oklahoma' redbud should be grown in full sun or partial shade on moist, well-drained soil. This is one of the nicest (if not the nicest) redbuds and should be grown by the industry. The glossy leaves always draw attention to the tree even by those unconcerned about trees. It is highly drought tolerant once established and grows well in all areas within its hardiness range.
Propagation is by budding only.
Pests
Treehoppers lay eggs under the bark of twigs. The insect itself is not seen but the white, sticky froth covering the eggs is quite noticeable.
Scale insects can usually be controlled with horticultural sprays.
Diseases
Canker is the biggest problem with redbud. The fungus enters through wounds or dead and dying branches. Dieback begins as a canker on a branch. The cankers, at first small and sunken, enlarge to girdle the branch. Bark in the canker turns black and a crack forms between diseased and healthy bark. Once girdled, the part of the stem beyond the canker wilts and dies. There is no chemical control. Prune out diseased branches.
Leaf spots can be a problem during wet weather. Since the disease is rarely serious, no chemical controls are suggested.
Verticillium wilt attacks and kills redbud. Fertilize affected trees and prune out wilted branches.
