August 29, 2015

1 - The best way to control a grass weed in a grass lawn is to maintain a healthy lawn.

Yard and Garden August 29, 2015

Q.

How can I get rid of these stickers in the lawn without killing the grass?

-Boe R.

A.

The picture you sent looks somewhat like sandbur (Cenchrus species), but I cannot be sure from the picture. If it is not sandbur, it is probably another summer annual grass that can be managed in the same manner. A good resource from Texas A&M that describes sandbur management in lawns is AgriLife Extension.

Since you are trying to control a grass weed in a grass lawn, be careful with postemergent herbicides because you may also kill the lawn grass. Your best defense against sandbur and other lawn weeds is a healthy lawn. Sandbur has a tendency to germinate in weak, poorly maintained areas of the lawn and around the edges where the grass is often weaker or where sunlight can reach the sandbur seed to cause germination. At least in limited perimeter areas manual removal or preemergent herbicide applications may allow reasonable management.

Now that we are in August, control even with postemergent chemicals will be minimal and preemergent herbicides will be mostly ineffective. Your best management strategy now is mowing, catching the grass with the burs, and then disposing by burning or putting the grass trimmings into a black plastic bag in direct sunlight to "cook" the seeds to kill them before composting the cut grass. Leave the trimmings in the bags long enough to be sure the seeds are killed or you will spread weeds next year in your compost. This may take a week. Temperatures in the bags should reach 160 degrees to kill weed seeds.

An old piece of carpet or burlap drug across the lawn after mowing or when the seeds are dry may collect a lot of the seeds (not all) and help reduce the problem slightly. There will be seed persisting in the soil trying to germinate for many years. Maintaining a healthy lawn will be critical. If sandbur plants do begin to appear in the future, preemergent applications may be needed for several years until the lawn is well enough established to compete with the sandbur and other weeds.

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.

Links:

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

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

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