yes you can cut back the growing ends but it might do to just reroute them back into themselves. I know when to pick by the sound when you thump on them. Start now and when the sound changes it time to pick. Good growing, good eating.

fourtoomany, I know I'm very late on this, but I wanted to give a bit of caution on cutting back much of your vines, even those not producing fruit but on a plant that is. Vines equal leaves/greenery which equals food for the plant to feed its fruit. If the plants have a lot of fruit to feed, the quality may be less than expected if the food source is reduced.

Crystal