I think at this point, it's too late. It also depends on the variety since I find some are not good at making side shoots. Once a plant has made seeds, its job is done and time to shut down.

Hybrid variety or not? Are the seeds fully dry and mature? If you want to try it this late you will have to plan to cover and protect them from hard freeze. Awfully late for planting from seed in zone 5.

Dave

Not a problem as long as it's a variety that produces side shoots(like defrost said)... most do produce side shoots. Just clip off all stalks that have/had flowers on them, and wait for more side shoots. You might even want to let one stalk, or plant, keep flowering so you can save seed.

Kevin

Agreeing with defrost. This is best done by removing all summer sprouts as they start to flower.

Thanks everyone. The variety is "Packman".

I don't think seeds that sprout this late have a chance of making a crop by the end of Oct. In my experience, plants must be established and ready to take advantage of the last warm spells in Aug and Sept to do well.

I'm letting two DeCiccos bloom now because bee forage is falling off and the buzzing brigade likes the flowers.

IME Packman does a good job with side shoots.

I note that my seedling bok choi has been ravaged this month by pests that I don't see, undeterred by row cover. Another reason not to start broccoli if I can get side shoots from the spring planting.

catherinet: These are plants from the Spring, correct?

If so, do what I suggested. You have nothing to lose except a bit of time and water. Like nhbabs said, Packman does a pretty good job at side shoots. You probably noticed that when it was flowering. That's the key to the side shoots --- check them daily... if you see any separation at all, it's time to harvest. If you don't, within a few days, the stalk will get woody and they'll start to flower.

Kevin

Yes, these were planted as plants in the spring. I did get alot of side shoots from them, after the main part was cut. I'll give it a try!