When I came up to Catherby, all my patches where fixed. So I harvested and planted the herb, flower, and north crop patch. In the middle of harvesting the south patch, both the north and south grew weeds.
So I went ahead and dug up the south patch and waited 30 minutes like you said. I was able to weed it and get the normal 3, but it still shows weeds.
At least the herb patch is working, for now. It had ranaar planted, and I would hate to have to dig that up.