Lawn Burweed

Now that most of the kids are out of school and outside playing in the yard many of you have noticed a pesky problem.

Lawn burweed Photo: Joseph M DiTomaso, University of California- Davis, Bugwood.org
Lawn burweed
Photo: Joseph M DiTomaso, University of California- Davis, Bugwood.org

For some it could be primarily a cosmetic problem but for the ones who have baseball games held in the front yard it could be a painful problem for bare feet. Lawn Burweed is a winter annual that often goes unnoticed until the plant is fully mature. This weed germinates in the fall and has a pale green leaf that resembles parsley.The problem with this weed is that as the temperatures rise in the spring it moves into its reproductive cycle where it forms a spine tipped burr at the tips. These are the defense for the seed and also an inconvenience to pets and bare feet.

Control of this weed is much easier with a healthy turf going into the fall. Making sure that you lawn receives the proper amount of water, sunlight, and nutrients are the best defense against this weed as well as others. Chemical control is also used in the fall as a pre-emergence and late winter as post-emergence. For pre-emergence control, products that have Isoxaben, Prodiamine, or Pendamethalin can be applied in late fall. For post-emergence control products that contain Atrazine is safe on Centipede and St. Augustine and on dormant Bermudagrass. Products that contain 2,4-D, dicamba, and mecoprop can be used on Bermudagrass and Zoysia but can injure St. Augustine and Centipede. Anytime you use chemical control always read and follow label directions.

Lawn burweed poses a unique problem as it almost always escapes our eye as we do not travel our yard often in the winter months but almost always find it in the spring and summer months when it is too late. For those that have this problem now remember that a full, lush turf is a great defense.

Turf matted with lawn burweed Photo: John D Byrd, Mississippi State University, Bugwood.org
Turf matted with lawn burweed
Photo: John D Byrd, Mississippi State University, Bugwood.org

Try to grow in these areas between now and when temperatures start to decline. Also, be prepared to spray in late fall to inhibit this weed from germinating and again in late winter to catch all of those that escaped. Once you have this pest under control the neighborhood pets and kids will love spending time outside. For more information call your local extension office and take a look at Publication 1322 “Establish and Manage Your Home Lawn“.

 

New Beginnings

For those who have lost the battle with weeds and winter kill over the past two years there is still a chance to turn it around. There was not as much turf was lost to winter kill last year as the previous winter but we did lose some due to improper timing and rates of herbicides. For example glyphosate, i.e. Roundup, is safe on dormant bermudagrass for nonselective control of winter weeds. However, this mild winter and spring warm up allowed the turf to break dormancy earlier than normal. That means that this safe application in previous years became lethal and for the most part had some severe injury on the established lawn.

Glyphosate injury to bermuagrass.  Photo: Jay McCurdy, MSU Extension
Glyphosate injury to bermuagrass.
Photo: Jay McCurdy, MSU Extension

Others have been waiting for quite some time to get out their chemical control allowing the winter and summer weeds to become a part of the landscape. Remember anytime you use any herbicide, fungicide, or insecticide always read and follow the label.

The first point to keep in mind is that a healthy lawn can battle many of the insect, weed, and disease pressures that it faces. This means that a little extra care when mowing, fertilizing and watering your lawn will help maintain its ability to outgrow/crowd out the competition. Also remember that some weeds can also be indicators for agronomic problems such as low/high pH, poor drainage, standing water, and compaction. So keep some of the next steps in mind when trying to maintain your landscape.

Insufficient light for turf grass caused by mature trees. Photo: Missouri Botanical Garden
Insufficient light for turf grass caused by mature trees.
Photo: Missouri Botanical Garden
  • The right grass has been selected for you lawn
  • Soil testing and right fertilization is being applied
  • Meeting the water and light requirement of the grass
  • Mowing at the correct height and frequency

Remember that the oak/maple that you planted in the yard 15 years ago was small enough to allow light to the base of the tree and now it shades a good portion where you are noticing some turf decline over the past couple of years. This can be solved in by a few mutualistic ways. One way is to plant a ground cover/flower bed and place some plants that can thrive in a more shaded environment.

Just keep in mind that all plants need sunlight while some can thrive on indirect sunlight. The second option is to work with a professional on trying to remove some of the branches in the tree allowing more sunlight to pass through the canopy and reach the base of the tree.

Chemical control is just one piece of the puzzle and should accompany the others stated.

Shaded areas planted with tolerant plants. Photo: Southeast Garden
Shaded areas planted with tolerant plants.
Photo: Southeast Garden

If you experiencing some declining turf or weed issues remember most grasses are pretty hardy and with just a few extra steps you can provide your family with many years of an aesthetically pleasing landscape to be proud of. For more information about establishing and maintaining your home lawn contact your local extension office and ask for a publication 1322.