Issue: August 14, 2004

Sand Burs and Goatheads in lawns

We have a terrible problem with sand burs in our backyard and have tried several treatments with no success. We even tried burning the yard where the stickers are located. The nursery told us to use an herbicide that did not work.
Rhonda Dickenson

Sand burs and puncture vine (often called "goatheads" because of the shape of the spiny seed capsules) are two common weeds that appear each summer in many New Mexico landscapes. I'll discuss both because some gardeners will have one, other gardeners the other, and some will have both weeds. There are some similarities in management and some differences due to the fact that sand burs are a grass and puncture vine is a broadleaf weed.

Both of these can be managed by maintaining a healthy, dense lawn grass. The weeds do not germinate well in a healthy lawn but appear in thin areas of the grass or around the perimeter adjacent to driveways and sidewalks. Proper lawn mowing, watering and fertilizing will reduce the problems with both weeds.

As you identify the weed in your lawn, manually remove it (by pulling or digging) to prevent it from forming seeds that will continue the problem next year. However, there are seeds from previous years lying dormant in the soil, and these will cause future problems. Don't let this year's weeds make seed to add to the problem. A healthy lawn will help with problems in subsequent years.

In weed management, it is important to use the proper herbicide. Once they are growing, grass weeds (sand burs and others) must be treated with a grass herbicide. Puncture vine is a broadleaf weed and must be treated with an herbicide specific to broadleaf weeds (which will not control grass weeds). There are also non-specific herbicides that will kill all vegetation (such as glyphosate-based herbicides). These post emergent herbicides can be used to help you manage the weeds and reduce the number of seeds formed.

Both sandbur and goathead are weeds that die in the fall. They must sprout again from seed each spring or early summer. For this reason, they may be managed by use of pre-emergent herbicides that prevent seeds from sprouting. If applied early enough, this will greatly reduce the problem each year. However, it is too late to use pre-emergent herbicides this year because the seeds have already sprouted. If you choose to use these next year, read and carefully follow the label directions.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!