Keith Mickler's column: Time to Kick the Summer Weed Invasion

 

 

By Keith Mickler

 

Weeds (a plants who virtues have yet to be discovered) a foremost concern in your lawn last summer? If so, now is the time to make that application of herbicide(s) designed to stop or at least reduce the amount of weed problems. These herbicides are known as preemergent herbicides. They work by killing the young weed just as it starts to germinate by either killing the first root or shoot to emerge from the seed.

 

Timing the application for summer weeds such as crabgrass should be around late February to late March when day temperatures reach 65° to 70°F for four to five consecutive days. If you wait until you see weeds, too late. You must apply the product just before the seeds germinate and emerge.

 

If you are seeing weeds right now, they are not summer annuals but winter annual. Summer annual weeds aren't up and growing yet we hope. A typical summer weed germinates from a seed in the spring, grows during the spring and summer, produces flowers followed by seeds in early fall and then is slayed by cold weather in late fall or early winter. Summer weed seeds are still dormant now awaiting warmer spring temperatures to germinate and emerge to glory, kind of like people.

 

Some of our favorite summer weeds include crabgrass, goose-grass, spotted spurge, burn weed, etc. There are many, many weeds out there; but one way to look at this is weeds are mean, green and tuff.

 

If your lawn has a history of summer weeds, one option is to apply a preemergence herbicide. But remember timing is perilous in order for the herbicides to work. The other option is to move to a home with no lawn.

 

Some preemergence herbicides to look on the shelves for are: oryzalin (Surflan), benefin (Balan), pendimethalin (Halts), benefin + trifluralrin (Hi-Yield Crabgrass Preventer, Team) benefin + oryzalin (XL), dithiopyr (StaGreen CrabX), prodiamine (StaGreen Crabgrass Preventer).

 

For season-long weed control, another application may be needed about six weeks after the first application. Once the herbicide is applied it must be activated. This can be accomplished by either irrigation or rainfall upon the lawn following application. Because many preemergence products may interfere with lawngrass seed germination, delay reseeding six to sixteen weeks after application.

 

Overuse or two much of some preemergence herbicides can cause damage to your grass. So only apply if there is weed problem – in this case, if you have had a history of summer weeds. Otherwise, save your money and time. Use preemergence herbicides only on lawns that have been established for at least a year. These products can/will severely damage newly planted lawns.

 

It is the user's responsibility to read and follow all label directions and precautions when using any pesticide, including herbicides.

 

Keith Mickler is the County Coordinator and agriculture agent for The University of Georgia/Floyd County Cooperative Extension. Located at 12 East 4^th Ave, Rome, GA 30161 (706) 295-6210. Office hours are Monday-Friday 8:00 a.m. - 5:00 p.m. The University of Georgia Cooperative Extension - Learning for Life. Agriculture and Natural Resources, Family and Consumer Sciences, 4-H Youth.  An Equal Opportunity/Affirmative Action Institution. To obtain extension publications please visit our web site www.ugaextension.com or contact your county Cooperative Extension office.