Management Tools


After you assess which invasive plant species to target for management, the next step is to evaluate options for control. There are a number of tools available. They include everything from manually or mechanically removing plants to using biocontrol methods or chemicals. Understanding the biology of the targeted plant, as well as its population size, degree of threat and tools that have proven successful by other practitioners should all play in to your decision of what tools to use. In most cases, more than one tool will be necessary to control your target.

Mowing and Cutting
 
Mowing and cutting can reduce seed production and restrict weed growth, especially in annuals cut before they flower and set seed. However, some species re-sprout vigorously when cut, so be sure to consider the biology of the plant before cutting.
 
How To
Mowing and cutting are often used as primary treatments to remove aboveground biomass, in combination with prescribed burning or herbicide treatments. It is important to collect the cut plant fragments to prevent roots and seeds from washing or blowing into uninfested areas when they can re-sprout. The timing of this control is key – be sure to remove the plant before they set seed, otherwise you will have to start over again next year.
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Girdling
Girdling is one form of cutting that is often used to control trees or shrubs that have a single trunk. It involves cutting away a strip of bark several centimeters wide all the way around the trunk. The removed strip must be cut deep enough into the trunk to remove the vascular cambium, or inner bark, which is the thin layer of living tissue that moves sugars and other carbohydrates between areas of production (leaves), storage (roots), and growing points. This inner cambium layer also produces all new wood and bark.
 
How To
To girdle a tree, cut parallel lines approximately three inches or more apart around the circumference of the tree. The cuts can be made using a knife, ax or saw, and should be slightly deeper than the cambium. Strike the trunk sharply between the cuts using the back of an ax or other blunt object. The bark should come off in large pieces and prevent the tree from any further growth. It is important not to cut too deeply into the trunk because this could cause the tree to snap and fall in high winds. To determine the depth of the cambium, make two short test cuts and strike the bark between the cuts. After several strikes the bark should come off intact, exposing the cambium and wood (xylem) below.
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Girdling is typically less labor intensive than cutting and removal of a tree, is inexpensive and kills only the targeted plant. It also leaves no residue except the standing trunks. In addition, a dead standing tree (snag) can provide valuable wildlife habitat, and if left to decay, allows the nutrients of the tree to be returned to the system, rather than being removed and deposited elsewhere. A few species, notably tree of heaven (Ailanthus altissima), should not be girdled because they respond by producing many fast growing root and stem sprouts. Therefore, before girdling, find out if the target species responds by re-sprouting. If so, use another control technique, such as cut stump or hack and squirt herbicide applications.
 
Proper Disposal
All plant material should be bagged and properly disposed of. Composting is not recommended for most invasive plants because the seeds may still be able to germinate. You may want to place the plant material in a heavy-grade plastic bag and leave in the sun for several weeks. This will help kill the seeds. Then composting that material becomes a viable option.