|I have gravely sandy soil with heavy crabgrass. I have reseeded in the fall and plan to do it again in the spring. I need to stop the crabgrass and allow the grass to grow. I intend to use liquid weed killer and scotts haults after the seed has grown to about six cuttings. Not sure how to seed and stop the crabgrass when seeding.
|Answer from NGA
February 23, 2010
|Crabgrass starts germinating when soil temperatures are 50 to 55 degrees F for ten or more days and germination can take place over a 6 week period. Pre-emergence herbicides provide excellent weed control for crabgrass but they last only about 30 days. The compound prevents the weed seed from germinating, but it will not kill the newly sprouted seedlings. Late March to early April is an ideal time to apply pre-emergence controls. The difficulty in controlling your crabgrass is that you want to overseed and the pre emergence herbicide will keep the grass seeds from sprouting. At this point, you might want to try raking it out or hand pulling. Use a corn gluten based pre emergent on your lawn to keep the crabgrass from sprouting and wait to overseed this fall. A dense stand of turfgrass will help keep the weeds from growing back. A fall fertilizing and overseeding can also limit spring problems. Best wishes with your lawn.
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