Q. I have planted myoporum to rid one area of my lawn of Bermuda grass. Yet the grass seems to grow more. How long should it take myoporum to overtake and rid the area of Bermuda? Is there a better groundcover for my area to use instead?—J.P., Waddell, AZ
A. Myoporum is a great groundcover for your area, but Bermuda is so tenacious that it must be eradicated before you plant something over it. Otherwise the watering and fertilizing of the myoporum will just encourage it. Bermuda spreads by stolons beneath the soil. The stolons are often 12 or more inches underground, so they can survive, spread and pop up where unwanted. Here are a couple ways to get rid of it:
You can dig/till it up, removing all the roots, rhizomes, or stolons. You may have to dig two feet or more. Or, you can solarize, in which you let the sun do most of the work to kill the grass. You need to solarize during the hottest part of the summer, for up to three months.
To solarize, moisten the soil, lay a 4- to 6 mm sheet of clear plastic over the grass and seal the edges of the plastic with rocks or soil. This will naturally heat the top four to eight inches of soil to more than 140 degrees F, depending on soil type and temperatures. If you spread fresh manure on top of the grass before putting down the plastic, that will heat things up even more.
Or, you can use a product with glyphosate, such as Round Up. Glyphosate is a systemic--when it's sprayed on a plant, the plant absorbs and distributes it throughout its system. Eventually it kills the entire plant, including the roots. Caution: The spray can drift to other plants, particularly if there is any breeze, and kill them too. Glyphosate doesn't remain in the soil, so you can plant other things after the Bermuda is gone. Be sure to follow product instructions exactly. Good luck!
—National Gardening Association
