Killing grass

[snlmama]

Thought I"d post here for some ideas - we want to get rid of some of the grass in our yard and put in a playscape for the kids. It's a perfect location b/c it's pretty shaded, etc. But, we've had limited success getting rid of the grass in other areas of the yard. It's St. Augustine, if you are familiar w/ that. And we're in Texas, so the stuff grows like a weed. :/

The plan right now is for dh to mow it w/ some special blade on his mower that will cut off the top part just below the surface, then put down landscape fabric, then put mulch on top. I know the *best* plan would be to dig it all up, but that's going to be really exhausting in our clay soil. :/ Dh wants spray w/ RoundUp, but I'm worried about spraying that where we plan to have kids playing. Anyone know much about it? We don't normally use chemicals unless we feel it's absolutely necessary (to kill fire ants near the play areas or patio, namely). Anyone know of organic grass killers? Will vinegar or salt (or both work). Anyone have success w/ that?

TIA

[katiekind]

I don't know if St. Augustine is the unkillable dude of the grass world--if so, maybe this won't work. But what I've seen people do around here to kill a patch of grass is put down a black tarp over the area they want to kill. Presumably the heat of the sun cooks the grass under the tarp. Maybe your spot is too shady for that to work?

[snlmama]

Thanks. We may try that. The big issue will be getting the tarp to STAY there for awhile. And, no sun, but it does get really hot here. :shrug

[Iarwain]

You'll have to weight down the edges of the tarp well, of course. Actually the cheap black plastic on a roll works quite well. It is not an instant solution, but it does work well. The longer you leave it down the better it works. A month is usually adequate, but if you left it for two or more in the heat of summer that would kill not only the grass but the grass and weed seeds and roots as well reducing the likelihood of anything growing back and pushing through your landscape fabric when you put that down.

[snlmama]

OK, thought I'd update on this. I remembered that when I accidentally got some vinegar on my Elephant Ears (while pouring it in the sandbox to clean that) the ones it got on died. So, I decided to try some vinegar on the grass and it worked. Killed the test spot in a few days, so we poured vinegar over the entire area, then put down landscape fabric and covered it w/ mulch.
Thought I'd share that tip for anyone needing an organic grass killer - just plain old white vinegar. I'm planning to just pour it over the area every now and then to keep stuff out (it also kills bugs and is a good disinfectant).

[katiekind]

Good! That's great to hear how it worked out for you!

[Soliloquy]

I vote a big fat NO on the Round-Up. It's very toxic.

Here are some things to try:

Make a strong solution of Borax and water. Sprinkle it on with a watering can. But, be warned, it takes years for the Borax to leech out so NOTHING will grow there for several years. A mild solution of Borax is good for killing creeping charlie. My dad made it too strong and now they have a big bare spot in their yard. If you want to know how strong to make it, do a google search for Borax and Creeping Charlie or Lawn Ivy. Then, just make the solution stronger than recommended.

When putting up a playscape, it's recommended that you put down mulch to a 6-9 inch depth. That, combined with the black landscaping tarp should kill anything. An alternative to black landscaping tarp is newspaper, if you mulch heavily on top of it.