By Jim Schrenkel, Area Biologist

Herbicides can be just as important in managing wildlife and wildlife habitats as burning, timber harvesting, and planting food plots. Often herbicides are more cost effective and produce better results. Chemicals can be used alone or in conjunction with other management activities to enhance beneficial wildlife plant species.

There are many different herbicides on the market. How they work and what they control differentiate them. Herbicides are foliar (leaf) active, soil active, or both. Foliar-active chemicals must be absorbed through adequate leaf surfaces, but in some cases may be applied directly to plant stems. Soil active chemicals are pulled into plants through the roots. The chemicals are transported throughout the plants in both the food transport system (the phloem) and the water transport system (the xylem). Herbicides work in several different ways. Some inhibit photosynthesis, while others disrupt cell structure or growth. The effects of chemicals may be noticed immediately or may take weeks or even months. Some herbicides are non-selective, killing all plants, while others are selective against only certain plant species. Selective herbicides often enhance or promote beneficial wildlife plants, such as legumes, by reducing competition for nutrients and sunlight. 

Most wildlife requires diverse habitats to provide food, water, and cover. Different habitats are found in the five different plant successional stages. Plant succession is the change of plant species on a piece of ground over a period of years. Stage one is bare ground. If bare ground is not disturbed, then in stage two grasses and weeds will grow the first couple of years. In stage three, seedlings and brushy vegetation will take over, shading out the grasses and weeds. In stage four, young trees will shade out the brushy vegetation until stage five, when a mature forest is reached.

The herbicide prescription depends on the objectives of the landowner or manager. Herbicides can be used to maintain a certain successional stage, go back a stage, or even start over with bare ground. For example, if you want to maintain a grassy weedy stage, you could use a selective herbicide that will only kill woody plants, but not hurt grasses or weeds. Or if desired, a non-selective herbicide could be used at any stage to completely start over at stage one. Wildlife managers can use herbicides to manipulate plant succession to provide the needs of the wildlife they desire.

There are several different methods that can be used in herbicides applications. Broadcasting over large areas with either selective or non-selective herbicides will change plant communities. Spot spraying can be used to eliminate clumps of vegetation. Injection is used to eliminate single scattered unwanted woody plant species. All of these methods are useful in improving wildlife habitat.

Herbicides can be a safe and economical way to improve wildlife habitat. Certain herbicides require a Certified Applicators License for use, while others can be used by anyone. All chemicals must be used according to the manufacturer’s labels, directions, precautions and restrictions. Failure to do so can cause damage to desired plant species, wildlife and even humans. Check with chemical companies, farm supply companies, or natural resource agencies for the right herbicide to accomplish your objective.