I am often reminded of the Fram Oil Filter television commercials from the seventies where the auto mechanic had to give a car owner bad news about their car problems. The commercial always ended with the mechanic telling a person, “You can pay me now or pay me later.”
The moral of the commercial was to change your engine oil often and always, always use Fram oil filters to prevent engine problems. The same moral is true for lawn care and especially lawn weed control. No, not using Fram oil filters, but doing the proper lawn practices now to prevent weed problems later.
Weed control in a lawn or hayfield is more than spraying a weed killer. Certain weeds pop up because soil conditions are just right for their existence. With a little research you can learn why some weeds pop up and how to prevent them without the use of pesticides. Clover makes its own nitrogen and will pop up where little fertilizer is applied. Other weeds that might be present in soils with low nitrogen levels include chickweed, lespedeza, and broomsedge. Lawns with lots of shade, poor drainage and sometimes large trees or shrubs have problems with moss, sedges, rushes and dichondra. Do your homework before applying the weed killer or your problem will not go away.
Many times homeowners who treat their own lawns fail to treat at the right time when trying to control weeds. Plants grow vegetative in the first part of their life and most are easily controlled at this stage. Then plants enter a reproductive stage (flowering and seed production) where they are more difficult to control. Then plants mature and die. Most new homes today are sodded with Bermuda front lawns which look great in summer. But when winter comes, the lawn goes dormant. Then as spring arrives the dormant Bermuda lawn looks like a wildflower field with tons of winter annual weeds blooming.
This year “Pay me now” so you do not have to “pay me later.” Put out a pre-emergence herbicide to prevent those winter annual weeds from becoming a problem. Pre-emergence herbicides do not prevent weed seeds from germinating, but rather control the young seedling plants as they come in contact with the herbicide. Plus you will not have to look at those ugly weeds or their blooms. Sept. 15 –30 is the best time to apply a pre-emergence herbicide for winter annual weeds.
Just like motor oils today, one product will not work for all cars. One pre-emergence herbicide will not prevent all weeds. Correct weed identification is very important. You can bring samples by the Barrow County Extension Office for positive identification or go on line to check out the UGA Crop and Soil Science maintained web page, www.gaweed.com, to view PowerPoint slide shows or weed picture galleries. The power point presentations explain homeowner herbicides, weed control in Fescue lawns, weed control in Bermuda Lawns and weed control in Centipede lawns plus many other topics.
Pre-emergence herbicides are generally safer to nearby trees and shrubs compared to post emergence herbicides, however you cannot overseed for 2 - 4 months after application.
To be most effective, the lawn will need to receive a good soaking rain or be irrigated within seven days after application of a pre-emergence herbicide. Also, too much rain will dilute the herbicide. This spring many lawns treated with a pre-emergence herbicide last fall had heavy weed infestations due to the heavy rains last fall and this spring. If weeds escape your preventative efforts, then apply a post emergence treatment to your lawn in late February or early March. With all pesticides read and follow the label directions. These will tell you which grasses you can use each product on and safety precautions.
Examples of easily found pre emergence herbicides include Bayer Season Long Weed Control for Lawns, Green Light Amaze, Sta Green Crabgrass Preventer, Vigoro Crabgrass Preventer, Team, Halts, Surflan, Betasan, Balan, XL, Gallery, Snapshot.
Britt West is the extension agent for Barrow County. You can reach him at bwest@uga.edu.