San Antonio Express News
GARDENING, Etc.
Sunday, January 8, 2006
By Dr. Jerry Parsons
Since trees are the largest and most permanent plant form, they represent a huge, long-term investment of time, effort and money. Knowing the proper care for trees is essential in protecting this investment.
Along with proper care, special attention needs to be taken in selecting trees for the landscape.
First of all, have an overall plan or objective for planting a tree. Do you need shade, protection from wind, screening, a pedestrian barricade, or a colorful accent?
When planning, remember to consider the tree’s ultimate height and spread. Beware of planting too close to the houses, buildings, streets or power lines. For a complete list of recommended landscape plants for south central Texas and their ultimate height and spread, see:
http://aggie-horticulture.tamu.edu/plantanswers/publications/southcnt.html
Know your soil and climatic conditions. In our alkaline, rocky, caliche soils, many tree species that do excellent in other areas of Texas, do very poorly. Our sudden temperature fluctuations in the spring and fall kill many non-adapted trees each year.
In the nursery, small trees (6-8 feet height) may be your best investment, since they recover more quickly from transplant shock than larger specimens. Container-grown stock is generally the quickest to re-establish, followed by balled-and-burlapped and bare-rooted trees.
Whether planting bare-root or balled-and-burlapped trees or shrubs, the first step is to dig a hole of sufficient size. As far as depth is concerned, plant the tree or shrub about the same depth it was growing in the nursery. On a bare-root plant, the trunk or main stem is often discolored at the original soil line. This may be several inches above the upper-most roots. Plant a balled-and-burlapped plant so the top of the soil ball is at the soil surface or several inches above the soil surface–error on the side of planting too shallow rather than planting too deep. Trees will die because of wood rotting caused by soil being piled on the trunk.
When setting out balled-and-burlapped plants, the hole should be about 1½ times the diameter of the ball. The depth should be the same as the depth of the ball or several inches shallower than the depth of the ball. For container grown plants, the hole size should be just large enough to allow placement of the root system in the planting hole.
After setting the tree or shrub in the hole, always use the same soil which was dug out of the hole as backfill. Adapted trees and shrubs do not need soil amendments to help them become established. Water the plant thoroughly after planting with a slow flow into the planting hole to settle the soil fill around the root system and remove all air pockets.
Fertilizer should not be used on new plants. It should be used only after the plant has become well established in the new location which takes 6 – 8 months.
Water your shade trees slowly and thoroughly during dry spells. Fertilize in late February with a complete and slow-release fertilizer such as 19-5-9. Use seven pounds of this fertilizer per inch of trunk diameter, measured 12 inches off the ground.
Dr. Jerry Parsons is a Professor for Texas A&M University and a Texas Cooperative Extension Horticulturist for over 30 years in South Central Texas. For more information on this or other horticulture topics, go to www.plantanswers.com and our County Extension website at http://bexar-tx.tamu.edu
