I have planted clover during May and later even. Many times I don't see much evolve in that particular season/year when I do it this way. However, the following year it seems to really come along. Personally, I would probably do an Oats & Clover mix if I was to plant it. I'll also say this as this has been my personal experience in my area of East TN...I'm not a huge fan of clover plots (I know it's blasphemy). People can say what they want about me, but I have the trail cam footage to prove it. I never saw or captured on film much activity in clover plots. However, I took these same plots and planted them in Chicory and the increase in deer presence was AMAZING. My point is, try the clover but I would monitor it. Just because everyone preaches clover is the way doesn't mean your deer will gravitate to it. Maybe there's just an abundance of clover everywhere surrounding my property - I don't know. All I know is, they flat out tore the chicory up from Summer to Winter. Of course, chicory is expensive - but what's the cost in planting something the deer don't particularly care for?