I have 5 grape vines that have produced well this year. But I do have a problem. They do not seem to be maturing. They are still very sour. Is it possible that given more time they might mature completely? How long can I leave them on the vine? Thank you. Bert Lake Cowichan
give them time, they should ripen, i've picked grapes when there was snow on the ground in northern california.
In this climate grapes will continue ripening until about the end of October, as long as the vines still have green leaves.
