Well, we finally have the huge, sunny yard we’ve been wanting . . . and it’s covered with zoysia grass. Zoysia is a drought-hardy, warm season grass, which means you can’t just kill it by letting it dry up. It will also readily invade our garden beds (which will be most of the yard) if we just till and try to work around it, so it’s got to go.
This resource from the University of California lists several methods for removing warm season grasses. Any of the effective methods will involve noticeable time and money for a yard our size.
Our plan is to use solarization, which basically bakes the grass to death by trapping the sun’s heat underneath a sheet of thin plastic (you know, the good ol’ greenhouse effect). This means that we have to buy a lot of plastic, and stay off of the yard for several weeks.
We will likely use sheet mulching in a couple of areas, primarily to create some walkways through the plastic-covered portion of the lawn. This may, in some ways, be the “greenest” option, especially if we obtained enough old cardboard, but at 4 layers of cardboard over the entire yard, that’s a LOT of cardboard (and mulch, which you need to cover the cardboard).
All of the plastic for solarizing is far from the greenest thing ever — not sure how to weigh that against multiple rounds of Round-Up — but in the end, we’ll be on our way to having a space that is growing food, not lawn (so ready to be done with the mower!).
Solarization has additional benefits, according to the U of C guide: “This method not only kills grass but can also improve soil structure, increase nitrogen availability and reduce some species of nematodes and soil borne disease.” Sounds good to me!
If all goes well (i.e,. we can afford to buy All. The. Plastic. and the solarization works), we will be laying out our garden beds, perhaps in time for some fall planting. Once the grass is gone, we’ll bring in some compost as well as any indicated soil amendments (Matthew took soil samples for testing waaaaayyy back in December), and get our garden on!
We’d love to hear from others that have successfully used solarization (or other methods) to get rid of warm season grasses!