Identifying native trees of Texas for your landscape

January 13, 2005
DOROTHY PLOEGER
Victoria County Master Gardener

Have you ever wondered if native trees exist naturally in your landscape or if you can successfully add them to your design? The current trend in landscaping has embraced the value of native trees and plants, and the Victoria area is rich with an abundance of these treasures.

Many are found near area rivers and streams, and the pecan, bald cypress, cottonwood, American sycamore, anacua and multiple species of oaks are probably most prevalent. Magnolias and some palm trees further contribute to the list of natives. Most of the larger trees are quite old - and can be found already existing in natural settings in landscapes. In addition, the cherry laurel, Mexican plum, retama and Texas mountain laurel are attractive and popular smaller native trees. The smaller varieties suitable to this area can usually be transplanted successfully with proper technique and care.

Of the larger trees, the pecan is the state tree of Texas and is most commonly found in river or creek bottoms. It can grow 50 to60 feet tall, providing shade as well as food for wildlife. When harvested it contributes to the economy of many areas. The native pecan nut is small, but very flavorful. The bald cypress is also found near rivers and streams. It dates from the time of the dinosaurs, and some living specimens are more than 1,000 years old and, therefore, among the largest and oldest trees in the state. The leaves are light green and about one-half to one-third of an inch long. It blooms from March to April with male and female cones. Both of these stalwarts are majestic centerpieces to landscape design.

Other deciduous trees include the cottonwood, which grows quickly to reach heights up to 100 feet, and the anacua, (pronounced ah-NOK-wha), which also is native to banks of rivers and streams and is known as 'knock away, sandpaper tree or gum berry tree. It will thrive in arid sandy soil, but does not grow well in low, wet areas. It has fragrant, small white flowers in clusters in late spring and bears orange-red berries.

The American sycamore can grow to a height of 170 feet. Also found naturally in river bottom areas, the trunk has reddish brown bark that falls off in pieces to expose a smooth, white bark underneath. The leaves have a toothed margin and can be from 4 to 12 inches wide. It is the largest of any deciduous tree in North America and is planted as an ornamental. Though it is slow growing, it is long-lived. It blooms from April to May, and its light brown fruit about one-half of an inch in diameter is ripe in September and October.

Texas has a wide variety of native oak trees. Of the white oaks, the Southern live oak is more common to the east of the state while escarpment oak is more likely to be found in the western region. Other live oaks are crosses from these two oaks. Some botanists believe that they are the same trees, but there are differences in their tolerance to cold and other factors. They are both evergreens.

Other types of white oaks, such as the bur oak, post oak, and Spanish oak, are deciduous. The bur oak is more likely to be found near rivers and streams. It produces a very large acorn, which may be as large as 2 inches long and wide, enclosed in a cup with fringe on the edges. The leaves are from one-half to 1 foot long. The bur oak has a very long taproot that makes it difficult to transplant, but is very drought tolerant. It serves as an excellent shade tree. The post oak likes acid, sand and well-drained soil. It is probably the most common in this area and is usually found near the short-lived black jack oak. The Spanish oak grows from 15 to 30 feet tall. It is deciduous and the leaves turn a brilliant red in the fall. It likes well-drained sand loam and limestone.

The Southern magnolia is a very impressive evergreen tree that produces large, glossy leaves and a big creamy white flower. Unless trimmed, the branches reach to the ground, which is just as well because nothing will grow under it due to its shallow root system and dense shade. Mature height is 50 to 100 feet. The sweet bay variety of magnolia usually grows to 20 or 30 feet in height. It also produces fragrant white blooms 4 to 6 inches across. The leaves are smaller than the magnolia grandiflora. The sweet bay is almost evergreen.

Other smaller native Texas trees include the dwarf palmetto palm, the cherry laurel, the Mexican plum and the Texas mountain laurel. The dwarf palmetto typically grows to 3 or 5 feet, but may reach up to 20 feet. It requires moisture and shade until it becomes established. It likes sand, loam and clay, as well as full sun and can tolerate poor drainage and drought. Another evergreen palm is the Texas palmetto. It is a slow growing tree, reaching 45 feet after 20 or 30 years. The Texas palmetto is winter-hardy and thrives in areas as far north as Lake Livingston, Austin and Del Rio.

The cherry laurel is very attractive and is a large evergreen shrub or small tree that grows best in deep, moist, but well-drained bottomlands. Different from the palms, the cherry laurel is a fast-growing tree and reaches 35 to 40 feet. With age, the bark becomes almost black. It has shiny green leaves and bears tiny cream-colored flowers in tail-like clusters in the spring and small black berries enjoyed by birds in summer and fall. It is drought-tolerant if the roots are shaded. The leaves and fruit have a high concentration of hydrocyanic acid and are potentially poisonous.

Another small tree is the Mexican plum, which grows to 15 feet, but may grow taller. It has a beautiful fragrant white flower and produces purple-red plums that are very sour though they produce wonderful jelly. It is deciduous. Still another small deciduous tree is the retama. It reaches heights of 12 to 15 feet, sometimes taller. The retama produces fragrant yellow flowers 5 to 6 inches across from spring to fall. It can be invasive.

Concluding the listed varieties, the Texas mountain laurel is popular in landscapes. It is an evergreen and produces aromatic violet flowers. New leaves and stems appear hairy while mature leaves and stems are smooth. Branches grow upward in a slender canopy and can reach 35 feet in height. It grows best in calcareous or limestone soils. It blooms from March to April and its hard, red seeds containing quinolizidine alkaloids are poisonous when eaten. Mountain laurel is commonly used as a landscaping plant and works well with the natural landscape.

Our part of Texas is abundantly strong in trees and foliage. This overview should provide you with general identification information for landscaping with native trees of varying heights and growing patterns. For more detailed information on growing conditions, planting, transplanting and care of Texas natives, contact your local Extension office.