Eliminating zoysia without chemicals
Everyone knows zoysiagrass is a tough grass to get rid of. Why anyone would want to get rid of it, I don't know because zoysia is so gorgeous in the spring and summer.
But I found a page at URI that claims you can get rid of zoysia naturally, without chemicals. Here's the quoted passage:
"Many people plant zoysiagrass with the hope that it will solve all their lawn problems. After observing it for one or two winters, some people change their minds and hope to eliminate it. Their task is not easy.
"If you do not wish to use chemicals, or if complete or fast elimination is not required, you can use the following procedures.
1. Fertilize in September and October only.
2. Raise the height of cut to 3 inches or higher. After several years, this type of management encourages the cool-season turfgrasses to overtake the zoysiagrass.
"Faster elimination is possible. You would have to kill the entire zoysia lawn with a non-selective weed killer such as glyphosate, then renovate and reseed (CAUTION: glyphosate is not available for sale in Rhode Island--you will need to order it from an advertisement in a gardening magazine or newspaper)."
[End of passage]
The web link is:
Why would those 2 steps above (fertilizing only in September and October and raising the cutting height to 3 inches) encourage cool-season grass to overtake zoysia?
I can kinda see that the Sept/Oct fertilizing would favor cool-season grasses since they're waking up from their summer slumber while zoysia is falling asleep, but why would a 3-inch or more cutting height hamper zoysia in favor of cool-season grasses?
I think I usually cut my zoysia kinda high (because I almost always cut it on Wheel Setting 4 of a 5-setting mower. Would this step alone hinder my zoysia in favor of the cool-season grasses? I never fertilize in September or October.