SOME THOUGHTS ON WEEDS
Mary Ann Walz

With the advent of the monsoon season in New Mexico, there is rampant growth of weedy plants. And, depending on your perspective, some plants that others cultivate may be weeds in your mind. In the wonderful tome Weeds of the West, J.M Torell defines a weed as “A plant that interferes with management objectives for a given area of land at a given point in time.” Thus any out of place plant could be considered a weed.

Categories of Weeds

Invasive weeds are those plants that spread wildly and rapidly and have a negative impact on the environment. They out compete native plants and can severely degrade the land.

Exotic weeds are species that are not native to a particular area. They may also be invasive.

Toxic weeds are those that can cause illness or death to livestock, pets, or people.

Weed Control

Mechanical - This type of control includes pulling the weeds from the soil. Doing this actually disturbs the soil and may provide opportunities for other weed seeds to germinate and grow. It’s best to do this after a rain and when the weeds are small and have no seeds that are ready to germinate. Do not compost any weeds that have seeds.

Mowing annual weeds to prevent them from going to seed reduces the number of weeds you’ll have the following year. It may take several years of mowing to get rid of a large iinfestation of weeds.

Grazing with goats is a method used on rangelands but not very practical for homeowners. The goats will tend to eat many weeds before they eat the grasses. However, they may eat desirable plants too.

Sheet mulching the area with a thick layer of straw will help prevent weeds at the same time that you build the soil. Sheet mulching is easy and provides amazing results next spring as it improves the soil and chokes out weeds. Sheet mulching is done in layers of carbon (brown) and nitrogen (green) materials much the same as your compost pile. Start with a layer of green materials such as manure, grass clippings, or plant material (no weeds with seeds). Wet this layer. Next, spread newspaper 4 to 6 layers thick or a single sheet of corrugated cardboard and wet this layer. Add a thick layer of manure, about 6 to 12 inches and wet it. The last layer should be a carbon material and straw works very well. A flake of straw is about the right thickness and it should be wet

Biological - Some weeds can be controlled through the use of weed eating insects or weed diseases. The County Extension Agent can help with information on biological controls for specific weeds.

Chemical - weeds can be controlled with the use of herbicides but this must be done with extremecaution. Again, consult the County Extension Agent for recommendations.

The key to maintaining control over weeds is to learn to recognize them when they are small, treat the problem as quickly as possible, and use the least toxic but still effective means.