Green Horizons

Whether one talks about crop tree release (last issue of Green Horizons) or timber stand improvement (TSI), the fact of the matter remains, "How does one remove all the unwanted trees?: Undesirable trees with commercial value can be sold, making the operation an income-generating forest management activity. Some undesirable trees may be used for lumber, firewood or other products. The remaining unwanted trees can either be cut down or killed in place.

To be effective, the firdle must completely encircle the tree

Felling Trees
There are several things you need to consider if you decide to cut down these trees.

First and foremost is safety. Cutting small understory trees for firewood is one thing; cutting co-dominant and dominant trees from the forest canopy is another matter altogether. The tree you cut needs to fall all the way to the ground. Hanging trees are a huge no-no. Even the most experienced foresters I know cringe when they hang a tree. They know the risk of injury is high and every hung tree is different from the last.

Second is damage to the crop trees. Chances are good that unless you have been taught the technique of directional felling (how to fell a tree in the direction you want it to fall), you could end up damaging the very tree you are trying to save.

Third is accessibility. Unless you plan to remove all those down trees (not recommended), you will find it extremely difficult to move around in your woods. And you can forget about driving that new ATV out to your deer stand.

The last consideration is fire danger. This operation will place a lot of fuel onto the forest floor very fast. With that much wood on the ground, an innocent Missouri ground fire can grow in intensity and cause serious damage to your crop trees.

The safest and most efficient way to remove undesirable vegetation is to kill the trees and leave them standing. As they decay “on the stump,” the branches will come down a piece at a time. With no limbs, when the trunk eventually does fall, it will do very little damage.

Girdling
Girdling is the most common technique for deadening a standing tree. Girdling involves cutting a groove or notch into the trunk of a tree to interrupt the flow of sap between the roots and crown of the tree. The groove must completely encircle the trunk and should penetrate into the wood to a depth of at least 1/2 inch on small trees, and 1 to 1-1/2 inches on larger trees. Girdling can be done with an ax, hatchet, or chain saw; however, when treating large areas, a chain saw is the most efficient use of not only your time, but your energy.

A simple spray bottle can apply the labeled herbicide into the girdle

For those who prefer not to use pesticides, girdling can be used without herbicides. However, girdling alone is generally less dependable (particularly with hard-to-kill species such as red maple and hickories), takes longer to be effective, and can actually stimulate sprouting compared to when herbicides are incorporated into the treatment.

Water soluble forms of herbicides (such as Pathway and Tordon RTU) are most commonly used to get maximum movement of herbicide within the plant. These two herbicides are easy to apply because no dilution is required. They are applied by squirting it on the girdle until the cut surface is wet. Hand-held, pint or quart spray bottles, such as those available at local garden stores, are ideal for applying herbicide to the girdle.

Treatment with an oil-carried herbicide (such as Garlon 4) is recommended in the spring and early summer when “sap flow” is heavy. Water-carried herbicides will usually not be adequately absorbed to be effective during this period.

All herbicides are not equally effective in controlling different species. It is essential that you READ THE ENTIRE LABEL before using any herbicide. An excellent fact sheet from Randall Heiligmann over at Ohio State Forestry Extension (http://ohioline.osu.edu/for-fact/pdf/0045s.pdf) presents forestry herbicides commonly used along with recommended rates.

Herbicides, like all pesticides, are approved (labeled) for specific uses by the Environmental Protection Agency. These approved uses are listed and described on the pesticide’s label. Because pesticide labeling may change at any time, you should verify that a particular herbicide is still labeled for your intended use. At the time of this writing, copies of most herbicide labels and MSDS could be obtained online at the Crop Data Management System web site http://www.cdms.net/manuf/manuf.asp. Others are available through the individual manufacturer’s web site.

In future issues of Green Horizons, we will continue our “Removing Unwanted Trees” series, by looking at injection, basal bark, thin line, and cut stump treatments.