Q: Last weekend we took the solar blanket off our pool and laid it in our yard to dry. When we came back an hour later we found that the grass underneath had been burned. Now there is a big dead area in our zoysiagrass. What can be done and how long will it take to recover?
A: Now you know more about the garden practice “soil solarization” than you really meant to learn! Covering garden soil with clear plastic is a good way to kill weeds organically. It usually takes at least two weeks of sunny days to heat the soil down into the root zone to kill weed seed. I doubt you killed the zoysiagrass completely but it all depends on how long the plastic was in place.
At this point it’s just “wait and see”. Water the zoysiagrass if the weather gets really dry. Do not fertilize. I predict it will come back after several weeks’ wait.