Always planted end of August to beginning of September with good results down in Jackson, but that was zone 6a, this is zone 4b. Im thinking maybe in a week or 2 up here? depending on the rain forecast. Am actually kind of regretting not planting yesterday, with this good soaker we are getting right now, but the hot, dry extended forecast scared me off, plus this current rain wasn't predicted to be this much either. Sandy soil, Montmorency County.