Tuesday, August 21, 2007

Weed Control During the Drought

Having trouble managing weeds? This is just a reminder as to why that may be:

Why is it??? Crabgrass grows fine but my shrubs and lawn are drying up!

In a drought like this it seems that the only things that are growing -- are the weeds. But, now is not the time to apply herbicides to kill weeds. Herbicides don't work very well on wilting weeds. Post-emergence herbicides work better if applied about 2 days after rain -- BUT, that is not all. If it goes dry after that single rain event you may need to irrigate the weeds about 2 days after treatment to get them to die to the best of their ability.

Bottom line, post-emergence herbicides work better on actively growing weeds. If you do have to treat drought stricken weeds with herbicides, be prepared for a re-treatment after we get some rain because the weeds will likely come back.

from- Dr. Joseph C. Neal
Professor and Extension Specialist -- Weed Science
Two notes- Irrigated crops may have actively growing weeds that are sensitive to the herbicides and respond accordingly. Container nurseries may also want to consider an application of pre-emergent herbicides to control winter annuals.

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.