Question
Hi,

I live in Tucson, Arizona. I moved into a home a few years ago that had poorly kept grass. About a year and a half ago. I removed the grass, applied a pre-emergent, planted various desert plants and trees, and covered the bare ground with about a 2" coat of rocks. However, a few weeks after big rains, spots of the Bermuda grass always return, and I spend too much time in the back yard weeding. I have heard various suggestions for eradicating the weeds. For example, people have advised me to remove the rocks and lay down plastic, then reapply the rocks. I have heard that that has mixed results, and I'm hesitant to create a barrier that is going to keep water from getting to the ground. In Tucson, we need all of the water we can get. People have also suggested using a mesh, instead of plastic, but I have heard people say that grass can grow right through the mesh. Finally, I have heard people say that you need to apply a pre-emergent every year. Is that the best approach and, if so, can I just spray the pre-emergent on the rocks and hope that enough of it will "soak down" to the ground, or I will I need to actually move away the rocks to apply the pre-emergent directly to the ground. And how long and with what frequency should I do this for the next few years to permanently eradicate the grass?

Thanks for your help.

Answer
Hey, Matei.

The thing you forgot to do ws put down a barrier between the bare ground and your rocks. You can use plastic or mesh. Plastic is more effective. To make sure your plants get water, just cut the plastic around the plants leaving about six inches free of the plastic.

Fighting Bermuda grass is an ongoing battle. You will never permanently eradicate it because its seeds get blown around with the wind and the rain, so seeds will always land in your yard. It doesn't need much to put down roots and start growing.

If removing the rocks and putting down mesh or plastic is too labor intensive, you could be diligent in applying a weed killer to the Bermuda grass as soon as it shows up. I use Roundup. Make sure you follow the directions on the bottle as far as temperature and ground wetness.

If you choose not to remove the rocks and put down plastic or mesh, also use a pre-emergent every year in addition to being diligent with the RoundUp for the Bermuda grass that does make it.

Bottom line:

Best - bare ground with pre-emergent covered with plastic covered with rocks
#2 - bare ground with pre-emergent covered with mesh covered with rocks
#3 - bare ground with pre-emergent covered with rocks.

Regardless, though, you'll need to keep some Roundup handy for when your neighbors' Bermuda grass seeds land in your yard.

Hope that helps.