On this bright and sunny early fall morning I was thinking about all of the great gardening opportunities the cooler fall weather is bringing us in the Florida Panhandle. However, my thoughts drifted to the annoyances that the gardeners find when trying to enjoy their lawn or garden.
On the top of my list is stepping into a patch of burweed, which is in the sunflower family and is also known as spurweed. The leaves are opposite along the stem and sometimes resemble parsley. The main ways which burweed can irk the casual gardener are sticking to socks, sneaking in with the dog, or littering flower beds with its nuisance. It can also hide in the house and reappear when shoes are removed. This causes pain in both the foot and the ear.
Aside from herbicides, maintaining a healthy vigorous lawn will prevent weeds from taking over. If you lawn is reasonably healthy and only a few instances of this weed exist, try to mechanically remove them and encourage the lawn to outgrow them.
If cultural methods aren’t sufficient, science has given us several options to control this irksome pest. A widely used pre-emergence product for burweed control is isoxaben, which is sold under the brand name of Gallery as well as others. It prevents the weed from emerging from the ground when it germinates and can be used on St. augustine, centipede, bahia and zoysia lawns, as well as ornamental shrub beds. In northwest Florida, this herbicide needs to be applied in October for best results.
Herbicides which contain the active ingredients dicamba, 2,4-D or atrazine are good at controlling burweed as a post emergence control when applied from December through early March. Be careful to use reduced rates on centipede and St. augustine lawns, and never use more than the labeled rate. Later applications have less effect on burweed because as it matures it is harder to control. Additionally the burs, once present on the lawn, are hard to remove. As the daytime temperatures get a few degrees over 80, some of these herbicides may cause lawn damage so immediate application is advised. Try to keep the spray residue outside of the root zone of desirable plants to avoid injury and always follow label directions. Be aware that burweed reproduces by seed, so mowing it down will only increase the problem by burying the seed for fall germination.
The active ingredients mentioned above are present in a variety of ‘trade name’ products* available from your local garden center, farm supply or CO-OP. I hope all the northwest Florida lawns prevent burweed so that the spring lawns will be burweed free. Happy Gardening!
|Common Name||Manufacturer / Distributor||Brand Names||Type|
|Atrazine||Many||Many||Pre and Post Emergent|
MCPP + dicamba (3 way combined herbicide)
|Bayer, + others||Many||Post-Emergent|
|Isoxaben||Dow, Others||Gallery, others are now on the market||Pre-Emergent|
*Table reproduced from sections of the 2012 version of University of Florida’s Pest Control Guide for Turf Grass Managers.