I don't quite understand what you are wanting here, emcd124. Firstly I don't really get what you mean by having deliberately planted seed but then saying it 'volunteered'. Can you explain?

Also why do you want it to flower now? Does kale die in your winters? Normally it overwinters and flowers the following spring. If it does die in your climate I would think that some fleece or cloche protection might get it through so it could flower at the normal time. An alternative might be to dig it up and put it in a pot in a porch or garage window through the coldest weather. Kale is very hardy so it wouldn't need much protection.

Sorry if I wasnt clear. I spread seed in March and most of it came up in the spring. Then I pulled it all before summer and put in other plants. Then in the middle of the hottest part of summer, this little guy started growing. So I sowed it months before but it is a sort of quasi-volunteer.

I'm interested in saving seed from this plant because i'm drawn to the idea of a "fall kale" that would germinate and grow better in the hot parts of summer so I could have bumper crops going in the fall.

I have been trying to figure out if kale will overwinter and I cant find a lot of reliable advice. I'm in z5 northern Indiana. How do I overwinter it? Just put a cloche on top? trim the leaves down first?

I'm afraid can't help you with how to overwinter it because in my climate it is not an issue. The plants just stay outside. In fact winter is when we harvest most kale. I certainly wouldn't cut the leaves off. You could try asking over on the vegetable forum if you don't hear from anyone in your zone here. It's much livelier than this forum. Otherwise maybe just use a bit of horticultural fleece (Remay?)

Kale over-winters fine here in zone 7a. Seems like it should do OK in z5 but I have no real experience with that. I don't know of a way to change the flowering/seed forming time.