Question
when zoysia is dormant and yellow in the winter, can I poison other unwanted vegetation that is cropping up in the zoysia without hurting the zoysia?  I would be using round up.  I was hoping that it wouldn't wick into the roots of the dormant zoysia.

Answer
"Roundup" kills "any thing green that it touches". It is translocated to all parts of the plant for a total kill. It is deactivated in the soil. I would be reluctant to overspray any vegetation with the product unless I wanted to kill it. I have read that dormant zoysia can be oversprayed with "Roundup" but I have no experience of it. I expect that in such cases the zoysia would have to be completely dormant and the accuracy of application -'spot on'.