Plant of the Week
by
David Rodriguez
The promise of spring is upon us! Redbud trees, with their vibrant, purplish-hued blooms, are an excellent indicator of warmer days ahead, and the redbuds are now blooming all over San Antonio. Redbuds (or “Judas tree”) are named for trees and shrubs in the genus, Cercis. They are handsome plants in the family, Leguminosae (pulse family), and in early spring, are covered with different shades of deep rose, pink and purple or (rarely) white flowers that resembling pea blossoms. According to “Old World” lore, an ancient species redbud was the tree on which Judas hung himself. The Texas redbud’s most notable attribute is its brilliant, purple-red spring blooms, for which it is widely recommended as a small ornamental landscape tree.
Texas redbud, (Cercis canadensis var. texensis), grows as a deciduous small tree or multi-trunk shrub achieving a height of about 15-20 feet. The Texas redbud differs from the Eastern redbud in that the leaves are rounder, thicker, and very glossy. This variety is more drought and heat tolerant than its Eastern cousin. The Texas redbud is best known for the spring display of purple-red clusters of flowers on bare gray branches. The seed pod is flat, reddish-brown legume that ripens in the fall. Texas redbud is well adapted to the South and Central Texas alkaline soils, and has minimum distribution into both Mexico and Oklahoma.
Texas redbud is usually found growing native along limestone slopes and other upland sites of Central Texas. Texas redbud typically has a multi-trunk with thick, leathery leaves that are slick and shiny green on the top side, and pale green below. Leaves are simple with entire margins. The redbud flowers before the leaves open. The bark is thin, gray or reddish-brown with white “spots,” and densely covered with lenticels.
Planting sites for Texas redbud should be in an area that provides part shade, or full sun in a well-drained soil. Ideally, they tend to grow best as a small under-story tree that receives late afternoon shade. They tend to be happier in the summer time with that extra shading. The Eastern redbud tends to be more susceptible to drought stress and sun scald in our hot summers. Eastern redbuds often show marginal leaf burn in the summer time, due to the extreme heat intensity in our area. For that reason, the Texas redbud is the recommended variety for the San Antonio area.
When planting, Texas redbud trees should be spaced at least 20 feet apart. Do not plant under sprinkler irrigation where it will be watered with the lawn. San Antonio’s alkaline soils are perfect for planting, but please incorporate compost at the time of planting. The planting hole should be dug twice as wide, but at the same depth as the root ball. Trees are typically available and purchased in 5 or 10-gallon nursery pots. Carefully remove the tree from the container, gently supporting the root ball. Loosen the root ball, if there is compacted soil around the roots. Roots may need to be pruned if tightly wound around the pot. Plant the tree so that the root collar is above ground level. Do not cover or touch the tree trunk area with any surplus soil or mulch. A 4-inch layer of mulch around the tree will help in conserving water and aid in quicker establishment. Water the tree thoroughly and consider using a root stimulator.
The ideal time to select and plant your Texas redbud tree is late winter or early spring. Selection is best at your local retail nursery within that time frame. Select trees that are flowering so that you can chose the true color that is you desire. Texas redbud is a beautiful small ornamental under-story tree that can fit into any landscape. Check it out!
There are other redbud varieties to consider planting in your landscape, if you can find them. They include Mexican redbud, ‘Forest Pansy’ redbud or the White redbud. These trees all have their own unique and unusual characteristics.
Mexican redbud is smaller in stature, has smaller, glossier, and more wavy-edged leaves, and is more drought tolerant than the Texas redbud.
‘Forest Pansy’ redbud is an Eastern redbud variety that is a moderate grower to about 20 feet. The main characteristics include red twigs and beautiful, new shimmering, purple/red leaves, which fade to purple-green during the summer. The veins on the back of the leaves are a deep maroon and make a striking contrast with the light grey/green leaf.
White redbuds grow very similar to the Texas variety, except that they bloom white.
Remember, Learn and Have Fun!
David Rodriguez is County Extension Agent-Horticulture, Bexar County. For more information, call the Master Gardener ‘Hotline’ at (210) 467-6575 or visit our County Extension website at http://bexar-tx.tamu.edu, click under Horticulture and Gardening.