Land of the trees
Soil plays a large part when choosing the perfect small tree for your yard

November 10, 2005

JEROME E. JANAK
Victoria County Master Gardener

The Victoria County Extension Office and Master Gardeners are receiving numerous calls regarding recommendations for small tree varieties suitable for local landscapes. A major reason for this is the shrinking size of the average home yard. Trees commonly used in the large lots of older homes can grow too large for today's scaled-down yards.

Smaller trees can also be selected for placement under overhead utilities, near buildings or property borders, as screens, and in front yards and other areas for less obstructive views.

When selecting a small tree, keep in mind that the suitability of a certain variety will vary from one site to another. Growth patterns can also vary. There is no perfect tree for every site and situation. One factor that can greatly affect a tree's performance is soil condition. Victoria County soils can be divided into several greatly differing soil regions from the blacklands surrounding Placedo and Bloomington, to the caliche sands of some areas of Mission Valley and from the deep soils of the river bottoms to the upland sands of the Fordtran/Inez areas. The pH of each soil, the drainage capabilities of each individual site, and sun exposure are also factors that can affect the growth capabilities of a tree.

Choosing the right tree

Alkaline soils:

· The first recommendation is for those who insist on having an oak tree in the landscape. While most oaks grow too large for a small, modern lot, the lacey oak, recently named a Texas Superstar, fills the bill as a small to medium-size deciduous tree. Reaching a height of 20 to 30 feet and a spread of 25 feet, it is highly tolerant of heat, drought and alkaline soils. It will also survive on well-drained clay soils and shows resistance to oak wilt disease.

The lacey oak is also known as the blue oak due to the blue-green color of its leaves.But even superstars have limits. Research has shown that the lacey oak doesn't tolerate poorly drained soils and had a tendency to need some minor initial pruning. Planting on raised beds or berms can improve its growth potential in areas with less-than-desirable drainage.

· The Texas mountain laurel is an attractive spring-flowering small tree, also known as mescal bean. Its fragrant purple blooms form grape-like clusters in early spring. It normally reaches a height of 10-20 feet, good for a smaller landscape. It prefers well-drained alkaline soil.

Alkaline to neutral soils:

· The Anacacho orchid tree or Bauhinia congesta is a small, graceful tree 8-12 feet tall that is covered with white orchid-like flowers in the spring. If grown in full sun, it becomes fuller and bushier, but it will be a more open graceful tree if grown in afternoon shade. It prefers well-drained, neutral to alkaline soil.

· The Japanese blueberry tree (Elaeocarpus decipiens), recently introduced to the area, is gaining popularity and recommended by some of the local nurseries. It can reach 30-40 feet high and 20-30 feet wide, but can be kept smaller with pruning and shaping. It has bronzy new growth with white summer flowers and showy winter fruit. This evergreen shrub/tree is a good choice for use as a screen or can be used as a single specimen. It prefers full sun and regular watering. Unlike the blueberry marketed for its edible fruit, this "blueberry" is reported to prefer a more neutral to alkaline soil.

Neutral to acid soils:

· Little gem magnolia has the beauty of a Southern magnolia without the size. It is a dwarf cultivar reaching from 15-25 feet high, with beautiful foliage and showy white flowers that appear at a very young age. Left alone it will grow as a low-branching, dense and upright tree, but will suffer in heavy clay or alkaline soil, or inadequatesoil depth.

· The cherry laurel is a fast-growing large evergreen shrub or small tree with dark glossy green leaves that create a dense shade. It grows in most conditions, but seems to prefer more acidic soils since blackland soil that is not deep and loamy enough can cause it to get chlorotic. Its height can vary from 15 to 40 feet and its width from 10 to 30 feet, depending on the growth conditions. The leaves and fruit of the tree have a high concentration of hydrocyanic acid and can be potentially poisonous.

Adaptable to most soils:

· The ornamental pear is a variety recommended by several of our local full-service nurseries as a suitable small tree for most of our area. Two varieties include the Bradford and the Aristocrat, with the Aristocrat growing somewhat wider than the Bradford. Both can reach heights of 25-35 feet. A profusion of beautiful white blossoms can cover these trees in springtime, while in fall their glossy green leaves may form orange to maroon foliage. While tolerant of most soils, they can be short-lived and susceptible to fire blight.

· The crape myrtle is a Southern landscape favorite, adaptable to most soils. Some varieties grow to 20 or more feet, making them good candidates for the smaller lot. The white blooming Natchez is an excellent choice. Other small tree varieties include the light lavender Muskogee, the coral pink Tuscarora, and the light pink Basham's party pink. Though the crape myrtle naturally forms multiple trunks, these can be limited to only a few or even one, if desired. Trimming lower limbs to raise the canopy is also possible, but topping a tree to limit its growth is not recommended. A deciduous plant, the crape myrtle's exfoliating bark and graceful structure makes it attractive even in winter when its showy flowers are no longer visible.

· The redbud is another small tree known for its blooms. Its lavender-pink flowers appear in early spring before most trees have leafed out. It, too, may need to be pruned to raise the canopy and remove suckers. The Texas and Mexican varieties are recommended and are more drought tolerant than the Eastern variety which is not recommended at all for our area. Both recommended varieties reach heights of 15-20 feet with similar widths. These can be planted in either full sun or part shade.

· To provide light shade, the airy foliage of the Chilopsis linearis variety of desert willow is a good choice. This small deciduous tree provides showy, white and pink 3-inch trumpet-shaped flowers through much of the growing season. It grows 15-25 feet high and 15-20 feet wide in either sun or part shade and is drought resistant, but needs a well-drained site. It, too, may need pruning for shape or to raise the canopy.

· The wild or Mexican olive (Anacahuita) is another tree to consider. An evergreen growing to 25 feet, it has showy white flowers throughout most of the growing season. Its high heat tolerance, low water needs, and adaptability to a variety of soils makes it very desirable.

These are only a few of the small tree candidates that could work in our area. If the trees' needs are met and their characteristics taken into consideration, any of them can be suitable additions to the smaller lawns of today.