Gardening Help FAQs

Here are answers to some of the most common questions we receive about garden plants. You will find concise information on general gardening techniques as well as plant selection and care. For detailed information on specific plant pests and problems refer to our Common Garden Pests and Problems page.

Do you have additional gardening questions? Please contact us. Here's how.

Horticulture Questions and Answers

How do I control weeds in my lawn?

A weed is simply a plant that is out of place. Even desired turfgrasses can be "weeds" in the wrong location. As an example zoysia grass can be a weed in a turf type fescue lawn and tall fescue a weed in a Kentucky bluegrass lawn.

Weeds tend to take advantage of thin stands of grass and lawns that are stressed or poorly maintained. The old adage of "give them an inch and they'll take a mile" describes the opportunistic nature of weeds. In the Saint Louis area, cool-season lawns are generally more susceptible to weed invasion than warm-season lawns.

The first step in control and/or elimination of weeds is to employ good maintenance practrices which establish a healthy and thick stand of the desired turfgrass. These practices include planting the appropriate species of grass for the location and at the right time of year. Proper fertilizer applications, mowing heights, watering and core aerification to reduce soil compaction all contribute to a healthy, thick, weed-free lawn.

If weeds do become a problem, the next step is to identify the type of weed and select the appropriate control measure(s). Control measures for annual weeds vs. perennial weeds and grasses vs. broadleaf weeds can differ significantly. The Plant Doctors at the William T. Kemper Center for Home Gardening and many garden centers can help you indentify your weeds and point you to appropriate control stragies. The following is information on the types of weeds most commonly encountered in the home lawn.

Annual Weeds 
Summer Annual Weeds (and Biennials) 
Winter Annual Weeds 
Crabgrass Control 

Perennial Weeds 
Perennial Broadleaf Weeds in Lawns
Perennial Grassy Weeds in Lawns and Gardens 
Moss in Lawns 
Nimblewill
Violets in Lawns 
Wild Garlic and Wild Onion 
Yellow Nutsedge

University of Missouri Extenion IPM Booklets
Turgrass and Weeds