Primetime Newspapers
By Calvin Finch, PhD, SAWS Conservation Director, and Horticulturist
Week of January 17, 2005

Arbor Day and Tree Planting

            Gardeners all over San Antonio have received a letter from one of the national Arbor Day associations encouraging them to join the organization.  As an incentive, the organization offers a selection of eastern redbuds, dogwoods and golden raintree that are described as appropriate blooming trees for Texas.  The three species may survive in East Texas, but not here in San Antonio.  The golden raintree will survive in our area, at least until we have a severely cold winter.  The dogwood, however, will not survive more than a few weeks in our alkaline soil.  Eastern redbuds are drought sensitive and have trouble retaining their leaves during our summers. 

            It is fine to become a member of an Arbor Day association, but if you do join a group, suggest that they would do better to provide flowering trees such as the Mexican redbud, vitex, desert willow or ornamental pears.

            January is a good time to plant trees in San Antonio.  The trees have time to develop a root system before they must deal with the summer heat.  For shade trees, select from among live oak, Texas redbud, Monterrey oak, bur oak, chinquapin oak, lacey oak, Mexican sycamore, cedar elm or Chinese pistache.  If you would like a conifer, select from among Arizona cypress, Italian stone pine, Aleppo pine, Japanese black pine, bald cypress or Montezuma cypress.  Montezuma cypress is especially useful because it grows so fast, can tolerate wet or dry soils and makes a good shade tree in addition to having a conifer shape when it is young. 

            In addition to the blooming trees listed earlier, consider Texas mountain laurel, yaupon holly, Mexican olive, ornamental peach, oriental persimmon, crepe myrtle, Mexican plum and loquat for a small tree.  Shorter trees are important for a transition between shrubs and tall trees, and are especially important for wildlife habitat.  The Mexican redbud, loquat and Mexican plum have some shade tolerance.  Mexican olive is an especially interesting tree.  The tree has large fuzzy leaves and large white blooms that are showy all summer.  The “olives” are not edible except for wildlife.  Use Mexican olive as a specimen tree in full sun.  The tree will reach about 25 feet tall.  I also like the Red Baron ornamental peach as a landscape tree.  The blooms are rich pink red and hold on the tree for about 4 weeks in March, nearly twice as long as a regular peach tree.  In addition, the well-shaped tree produces a good crop of fruit.  Like Mexican olive, the Red Baron peach works best as a specimen tree in full sun.  To address the sensitivity that peach trees have to drainage problems, plant the Red Baron on a raised bed.

            Dig the hole for your new tree as deep as the rootball and 2 or 3 times as wide.  You can put a small amount of compost as backfill the hole but the native soil is best because the drainage matches that of the soil surrounding the rootball.  The trees listed in this column are well adapted to our native soils and survive just fine in the soil.  A planting hole full of compost or potting soil can be a death trap for the newly planted tree if water enters the hole easier that it drains.  During a wet period, the roots of a newly planted tree can be drowned.  It is also not useful to fertilize or apply a root stimulator at planting time. 

            Water in the tree generously at planting and then apply 4 inches of mulch over the root system.  Add water again only when the soil under the mulch dries to 1 inch deep. 

            Alamo Forest Partnership is a group of San Antonio organizations interested in tree planting.  They are sponsoring an Arbor Day program on February 5, 2005.  The event will also provide a free recommended shade tree seedling for the first 1,000 families that attend a quick 10-minute training session.  The Arbor Day celebration begins at 11am and runs until 2pm at the Sonny Melendrez Community Center (5919 W. Commerce).  Visit their website at http://www.alamoforestpartnership.org.  Find more information on selecting and caring for trees at www.plantanswers.com.