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To kill the crabgrass or not to kill?

Posted by sunfire01 z8 TX (My Page) on
Fri, Jun 11, 10 at 19:19

I have a lot of crabgrass mixed into my bermuda lawn. I would say 75% bermuda and 25% crabgrass. I fertilize with soybean meal every month and give my lawn 1 inch of water every week. Also I mow at 1 inch every 3-4 days. I can deal with the crabgrass knowing it will die at the first frost but was wondering if it would be best to kill it now or just let it go? I guess I have several thoughts on this starting with keeping my lawn mowed every 3-4 days to prevent seed heads. Would mowing this often keep the seed heads from coming up and producing more crabgrass next year? I will be using CGM for a pre-emergent this fall and spring with hopes of some help. I have some crabgrass killer from garden weasel which contains cinnamon but not sure if I want to go that route. I was hoping the bermuda would choke out the crabgrass but not sure if that will ever happen. Okay so what should I do? I'm open to suggestions and ideas. Thanks guys!!!

Follow-Up Postings:

RE: To kill the crabgrass or not to kill?

  • Posted by solc TX (My Page) on
    Fri, Jun 11, 10 at 20:58

you bought the garden weasel? I would try it out. See how it works.

RE: To kill the crabgrass or not to kill?

Probably easier to prevent then kill. Corn gluten meal, not corn meal, applied in the spring when the forsythias bloom. It's also good source of N.


RE: To kill the crabgrass or not to kill?

I'll be following this thread closely as I have the same problem!

I'd really like to know how well the garden weasel works too, at 19.99 to treat 100 square feet, it should be pretty amazing!

I put corn gluten meal down in the spring this year, but I still have LOTS of very healthy crabgrass in my Bermuda (about 25%).

Does it really die at frost or just go dormant?


RE: To kill the crabgrass or not to kill?

I've heard from the dirt doctor (howard garret) that findings are coming out that CGM are not as effective on healthy, organic soil that is biologically active. I think what it was saying that soil was so good that it broke down the CGM very quickly, thus cancelling its affect as an effective herbicide.

RE: To kill the crabgrass or not to kill?

How well Corn Gluten Meal works as a pre emergent depends on when it is applied. Many people, after applying it at the wrong time (too late in the spring, during the summer, in the fall) will tell you it does not work. If applied about 6 weeks before the "weeds" it is supposed to control start to germinate CGM works quite well, but if applied after the "weeds" start to germinate, or much longer than those 6 weeks, it will not be very effective.
If you can keep the crabgrass you now have from producing seeds you will have less (depending on how many birds fly over after eating crabgrass seeds) crabgrass next summer. Most of us have the species of crabgrass that is an annual and since it needs soils of a fairly warm temperature with the right amount of moisture to germinate working on getting your grass to grow in thick to help keep the soil cooler will help keep that from happening.

RE: To kill the crabgrass or not to kill?

I agree with the preemergent method. Because I spread some corn gluten back in February only on my front lawn, it has significantly less crabgrass than my back yard or vegetable garden. So while it does work, like kimmsr said: timing is everything. Spreading CGM in fall will take care of some of your cool season weeds that may be waiting to germinate but if you are more concerned about crabgrass, do it just before the forsythias bloom in late winter early spring.

Oh ya, and while mowing frequently may help, from my experience, the way crabgrass grows more horizontally than vertically you are going to miss a lot of seed heads.

RE: To kill the crabgrass or not to kill?

Oh, I put my CGM down on April 6th, some forsythia was still blooming then. I didn't realize its supposed to be put down just before it blooms...ah well, next year

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