A Lawn Service Expert Explains How and Why Weeds Invade Your Grass

Weeds can seriously destroy the image of your grass … you don’t need a lawn service expert to tell you that! A weed is a plant growing where it is not wanted. Lawn weeds can include unwanted grasses, broadleaf plants and sedges.

Weeds fight with grass for water and food and, if left unattended, they take over and your yard will look like the image at the top of this article:

So, what causes weeds to invade grass? Let’s hear it from a lawn service professional.

• Water: Streams or strong storms can carry weed seeds which end up on your lawn during flash floods. There’s not much that we can do to prevent this from happening.
• Wind: Weeds from your neighbors’ yards can take root in yours as a result of wind. This is also one of Mother Nature’s curve balls. In one swift breeze, your neighbors’ weeds could become yours. Seeds can blow right onto your beautiful, weed-free lawn. As with water, this can’t be prevented because we can’t control the wind.
• Pets and other animals: Your pets and other animals can bring weed seeds to your yard when they venture into wooded areas or fields. The seeds get caught in their fur and fall on your grass. Birds can also bring seeds to your yard.

PREVENTION

Start by identifying both the weed and your turfgrass. Maintain the recommended mowing height for your grass species and cultivar, and address thin areas, irrigation problems and other sources of turf stress. Healthy, dense turf is better able to compete with weeds; simply letting every lawn grow taller is not a complete control plan.

Pre-emergent herbicides target susceptible weeds before emergence, while post-emergent products target weeds already growing. Product choice and timing depend on the weed, turf species and label directions. A herbicide is not the same thing as fertilizer, and a single early-spring treatment is not appropriate for every weed problem. See the UF/IFAS weed-management guide for identification and management guidance.

For an overview of the process, read our guide to lawn weed control. Consistent mowing and lawn maintenance also help address conditions that allow weeds to establish.