How to get rid of bermuda grass without using chemicals

Question

I live in Northern California. I have found that Bermuda grass is extremely invasive and am ready to give up the lawn. We want to move to a native plant garden instead. I have been reading about Bermuda grass and the fact that the roots go down many inches. And that even just a small piece can regenerate and start invading again.

In looking on line many people suggest round up and multiple applications of it. I would prefer not to use round up as there are several people in the area raising bees in the area and there is some evidence that round up may impact insects in a negative way.

I visited a Master Gardener, trained by University of California at Berkeley. She suggested robbing the Bermuda grass of light for several months. She said to put down layers of newspaper (10 or so sheets thick) or use cardboard. Then top with several inches of compost and then repeat. She thought this approach would kill the Bermuda grass. She said to cut through the cardboard or newspaper when I go to plant in the spring.

Has anyone actually used this method successfully? In this area there are underground termites. Will the cardboard or newspaper attract them to my yard and house? Is this the best way to kill the Bermuda grass under these circumstances?

Answer 1

I live in Northern California, too, and have been trying different ways to get rid of Bermuda grass around the yard. This is what has worked best so far: improve the soil. Bermuda grass is a pioneer plant. It grows in hardpan/roadway clay substrate where all top soil has been removed. Starting in the spring, first step is to weed out just enough Bermuda grass to handicap its growth in warm weather. Next you need at least a couple of inches of compost and mulch (mulch to keep water in the soil). Then thickly sow a cover crop seed that will leave no room for the Bermuda grass to get started. I have had very good results with buckwheat and cowpeas. More mulch over the seeds to hold in the water. And more compost to feed the cover crop. Buckwheat grows very quickly and cowpeas will drill into the hardpan. As the buckwheat and cowpeas die back towards the end of summer I've tossed zinnia and marigold seeds in the soil and have had compliments from the neighbors. I've only seen a little Bermuda grass come up at the edges--and it came out easily because the rhizomes didn't have any hard dirt to lodge them. I should also add that I sprayed compost tea every week over the area to enhance the soil building process.

Answer 2

I have used newspapers and mulch in the past to try to control Bermuda grass. In my experience, while it cuts back on the vigor of it, you still will get pieces working their way through the layers of newspaper and coming up out of the mulch and around the edges. Bermuda grass, as you noted, has an extensive and deep root system that stores enough energy for multiple assaults on your barrier of choice.

I have had some success eradicating it in vegetable gardens in the South using solarization for a growing season or two. This is where you cut the grass back heavily (scalping it, in effect), water it well, then place heavy clear plastic sheeting over it during the hottest part of the summer and into the fall. This raises temperatures throughout the first few inches of soil enough to kill off a lot of things - including Bermuda grass roots. It might take more than one attempt, though, and if you have sidewalks or driveways nearby, roots can hide under there and then creep back out again once the plastic is gone. But, solarization can knock it back pretty well if done correctly, and you may be able to keep up with the rest manually or with the newspaper-and-mulch method while your new native plants get established.

I can't really speak to the termite issue except to say that I've read they don't really go for cardboard. Someone else more knowledgeable about their habits would need to chip in here.