You only prune the top third of the primocane after it fruits! The next year the same cane (now a floricane) will give a spring crop. After it does that cut it down it is done. As an alternative you can just cut your primocanes down (after they fruit!) every fall for a fall crop only.

You didn't mention the variety but if you only got flowers in October there are some issues. I have had good success even mowing off Josephine plants and still getting most of my crop before October frost. But more than likely you cut your back hard after you had substantial spring growth on the primocane canes. If you want to mow them off at the ground then do it either now or in the spring before growth starts. Varieties like Caroline or Heritage should then be setting fruit in August.

For my efforts I prefer not to double crop as floricane and primocane since it quadruples the labor involved. You could get both July and August crops as mentioned but mowing off old canes is much simpler.

I read that raspberry canes should be cut all the way down to the ground in winter when leaves are gone. I only want one crop in the fall. Is this the correct method to prune?

Yes, cut to ground. Don't even leave 6" stub or plant may start producing as a floricane. Timing is not so well defined. Although it should definitely be done while plants are dormant I prefer to mow off in early spring.

Yeah I cut back the spring growth too much Thanks I know whats going on now