dallis/johnson grass in St Augustine

ganeese – posted 12 July 2004 12:16

We moved into our home last fall and we have a large back yard that is Bermuda and a front yard that is St Augustine. At first glance our lawn look very good, probably the best looking lawn on our street, although that isn’t saying much. I don’t water much since we have been getting a ton of rain here in north Texas. I mowe high every 5 to 7 days. I have to mowe often because the dallisgrass we have grows so fast. I also fertilized this spring with Scotts Weed & Feed.

We have a lot of wide blade grassy weeds in our front and back lawn. It is mostly dallisgrass, a little johnson, and one more kind which name I forgot. The third looks like dallisgrass, but the seeds grow close the the growned in a half pod like thing.

I just sprayed MSMA on the back Bermuda lawn recently, but I don’t know what to do about the front lawn as I read that MSMA will kill St Augustine. There are spots in the lawn, all of which are right by the street, that are almost solid dallisgrass. I thought about using the MSMA or Roundup even though I will be left with a half dead lawn.

So should I just kill it with RoundUp and then try to get the St Augustine to grow over the dead spots? Is that my only option. I should add that digging up the grassy weeds is impossible since there are so many and the grass is so thick.

Also, on the bottle of MSMA it said to mowe the lawn down close before applying, but I read on another site that you should not mowe for a week or two before applying MSMA. So which is it?

I would also like to aske about putting compost on the lawn. I read that if you put down compost that good bugs would live in your lawn and keep it looking nice and that you can feed them corn meal. I know nothing about compost though. Can you by it? What kind to I need? How much do I use? How do I apply it?

grassnut – posted 12 July 2004 16:06

Hi there,

I’m not sure about the St. Augustine, but for the Bermuda:

1. You shouldn’t use weed and feed on Bermuda. Here’s some text I got from Scott’s website on the weed and feed.”Where Not to Use

Do not use on lawns of bahiagrass, bermudagrass, bluegrass, fine fescue, bentgrass, ryegrass, tall fescue or dichondra as severe lawn damage may occur.”

But now it’s done……? In any case ..

2. I never have had to mow any closer or change the interval before applying MSMA. I’ll re-read the label when I get home, but so far no problems.

3. Bermuda does best when kept at a shorter height. Probably around 1 to 1.5 inches is fine for most types. In getting to that height, try not to remove more than 1/3 of the blade each time you mow. Mow often, when ever you need to to make sure you don’t remove more than 1/3.

If you do this, and fertilize with about 1 pound of nitrogen/1000 ft per month during the growing season, the Bermuda will choke out all but the toughest weeds. Then you can use MSMA on them.

For the St. Augustine??? I say kill it and plant Bermuda. But I doubt that’s the answer you’re looking for. So let’s see what the St. Augustine experts have to say.

Good luck!Brad

ganeese – posted 12 July 2004 16:48

Now that I think about it it was probably just Scotts Weed Control not the Weed and Feed. I really hope that I didn’t over look something as plain as “don’t use on Bermuda”.

My husband doesn’t like the St Augustine anyway so I’m not opposed to getting rid of it. It is just the work and money that it may involve.

I heard some where a long time ago that you should mowe high to choke out weeds in your lawn, so when we moved in that is what I started doing. I didn’t realize that not all lawns should be mowed high. Will my back lawn be temperaraly brown if I mowe low?