September 2015
The Magic of Gardening

Fall is for Planting

It may not seem like it yet but fall is just around the corner. The last couple of years I have seen and heard of people losing both trees and shrubs from a combination of weather, stress and pest problems. This summer, I have had numerous calls about crape myrtles and young trees being infested with ambrosia beetles and quickly dying as a result.

Whether you are replacing lost trees and shrubs or maybe adding to your existing landscape, now is the time to start planning and looking for the plants you want. In the South, we can plant all year, but fall and winter are the best times to plant most trees and shrubs. Planting at the correct time of the year is a good first step, but planting correctly is just as important.

One myth about planting woody perennials, shrubs and trees is that you should treat the root ball with kid gloves. Actually, they would benefit greatly from a more vigorous treatment. There are several reasons for this, and surprisingly some of the harshest techniques result in the healthiest plants.

  A study of root systems after four years in the ground:
 
  This is what happens, above, if the roots are not washed and straightened ... versus below, how the roots look if washed and spread properly.
 

Containerized materials often have serious root problems. For instance, they may be pot-bound due to growing too long in the pot. Pot-bound plants will have circling root systems. If not corrected, the roots will become woodier and more troublesome the older they become. Eventually these circling roots may even girdle the plant and that can lead to the early death of otherwise healthy trees and shrubs. Circling roots and other misshapen roots can often be corrected by selective pruning or untangling and spreading them out.

It’s important to realize that roots respond to pruning in much the same way as the top of the plant. Pruning, whether on top or bottom of the plant, induces new growth. Roots pruned at transplant time, especially those that are excessively long or misshapen, will respond by generating new, flexible roots that help them establish in the landscape. It is vital that these new transplants are kept watered during this time and through the first summer after planting. Fall is cooler than summer, but it can be our driest season. Remember, even though the top of the plant is not actively growing, the roots will continue to grow all winter long. Water a little every day and over time increase the volume and decrease the frequency to a couple of times a week in the absence of rain.

A second problem with containerized plants can also be avoided during your root inspection.

In general, the medium in the container is a soilless mix with a large proportion of organic matter (usually pine bark). If transplanted with this bark around the root ball, this material will inhibit root development outside the planting hole. Furthermore, the porous texture of this planting medium will often lose water more rapidly than the surrounding native soil, resulting in increased water stress. It is much better for root establishment to remove as much of the potting medium as possible before the plant is installed.

I like to pull the root ball apart and gently wash the loose material off the roots. This may seem counterintuitive, but I assure you that research backs me up. Don’t throw the material away, but rather use it as topdressing over the soil along with about two to three inches of mulch. Don’t mound the mulch against the trunk, but leave a few inches of unmulched or very lightly mulched area before starting your mulch ring.

When digging the hole, I believe, as the car commercial used to say, "Wider is better." The hole needs not be deeper than the depth of the root system, but a wide area that is loosened to allow for easier root spread is advisable. Do not set the plant deeper than it was growing in the container. A better approach would be to perch it slightly higher to allow for some settling. However, don’t leave any roots exposed.

Lastly, in most cases, the soil within the planting hole should not be amended, but just loosened and placed back in the hole it came from. Organic soil amendments will likely do more harm than good, unless you have a deep, sandy soil. If your soil has a heavy clay content, adding a soil amendment to the hole could be the kiss of death. Water will percolate into the looser soil-amended hole, but it will not drain out very well. The roots will start to die, causing the plant to wilt and causing you to think the plant needs more water. That’s why, when someone calls me to ask why their newly planted tree or shrub just wilted and died, I may sound like Hank Kimble from "Green Acres." Hank was the county agent who always made seemingly contradictory and non-committal statements. He would say, "Well, your plant had too little or possibly too much water." Since the symptoms are the same, it is impossible to tell without an examination of the root system, but proper planting can avoid the need to ask the question.

The Alabama Cooperative Extension System has a great new publication, "Establishing Woody Ornamentals, ANR-0410," I wrote last year that you can get from your local County Extension office or online at www.aces.edu.

Tony A. Glover is a County Extension Coordinator in Cullman County.