Many garden books promote methods such as the “Lasagna method” where you layer materials such as cardboard, black plastic, compost, mulch, etc., onto grass and create a garden. In Southern California we must evaluate such recommendations carefully: Does the person who is telling of great Lasagna success live in a year-round growing season, or do they have the benefit of a frost to help eradicate weeds and pests? Does the storyteller have Bermuda grass (Cynodon dactylon)?
Here in Southern California, without frost of any significance and with nearly every backyard being populated with Bermuda grass, there is only one viable solution: dig, dig, dig some more, and plan to dig again.
Low-till methods like the Lasagna layering don’t work because deep underneath all those layers, Bermuda will lurk, yellowed and bleached, but still very much alive. When given half a chance, it will tunnel up through any holes it can find in the barriers (it can create them) to take over your new patch with gusto.
We might tell ourselves we’ll use chemical methods like Roundup “just once,” and then return to organics. We’re kidding ourselves. Bermuda will lurk under the edges of the nearest concrete and come out again, demanding that we reapply chemicals again and again. (And each time we reapply those chemicals, we must rebuild our decimated soil life all over again.)
The surfactant allows Roundup to get inside the plants that we eat. You can’t wash off the contaminants. Roundup is “in the plant, not just on the plant.”
-- Maria Rodale, quoting Dr. Warren Porter, University of Wisconsin, Madison (R1)
Some gardening manuals advocate “no till” methods. When we consider such things as the long, delicate, microscopic threads of the mycorrhizal fungus which reach webs throughout our soils, “no till” sounds like a really fine idea. But pure “no till” isn’t a viable option for a new garden on a site with Bermuda grass and no hard frosts.
At the Community Garden at Holy Nativity, we removed the Bermuda by digging and cutting it out, then raking to eliminate all the stolons that we could. Then we tilled the garden area by using a rototiller.
Never use a rototiller prior to Bermuda grass removal – you will simply make your Bermuda problem worse by chopping it up. Each tiny bit will resprout!
Next section: "Bermuda grass containment in a frost-free area"