I am posting this again following Registration and submission of email address.
I have had a thornless domestic blackberry for several years which has vigorous canes and foliage. My problem this year is that whilst I had plenty of large fruit I was only able to harvest about 50pct because the fruits would not properly ripen. Is there any measure I can take to rectify this situation, or should I dig the plant up and replace it with such as the Loch Ness? The plant is against a westerly facing tall timber fence and I live in Burgess Hill, West Sussex.