Where Did All These Weeds Come From?
Every year when it nears the end of September, we get a lot of folks that come in to the Grass Pad and say, “I followed your fall lawn renovation program; I used your weed-free grass seed. Why do I have weeds in my yard?” Our response is “Well, it means you really did it right!”
“Yes, You Did it Right”
When properly preparing your lawn for fall overseeding, you created a pathway for grass seed to reach the soil. If grass seed didn’t reach the soil, it would not grow. Raking, verticutting, dethatching, or core aerating are all methods to ensure seed to soil contact.
See Related: How to Overseed your Lawn
Soil Preparation before Overseeding
Disturbing the soil (verticutting, aerating, dethatching or raking) exposes soil and any pre-existing weed seeds that lay dormant in the soil. These weed seeds could be from last year or several years ago, suspended under the soil, too deep to germinate waiting for their opportunity to spring into life.
See Related: Aeration vs. Verticutting
Controlling Broadleaf Weeds after Seeding
Dandelion, clover, spurge, and numerous other broadleaf weeds are stimulated as well. If you should have just a few weeds here and there, pull them by hand. However, if you are overrun, fall is an excellent time to control those broadleaf weeds. Perennial broadleaf weeds are busy sucking up much-needed nutrients to store for overwintering. An application of Gordon’s Trimec or Speedzone can be applied 28 days after grass seed germination. A fall application of Gordon’s Trimec with Uncle’s Stikit, spreader sticker or a granular application of Loveland Weed and Feed will be quickly absorbed by the broadleaf weeds and is sure to kill to the roots.
Controlling Crabgrass after Seeding
Grassy weed seeds appreciate the same fertilizer and additional watering from your fall renovation program and flourish. Don’t panic – annual grassy weeds will be slow to germinate as soil temperatures cool in fall. Mother Nature will take care of these annual weeds at first frost. Using Prevent, crabgrass preventer in mid-April will eliminate their return.
See Related: Controlling Nutgrass