What are you comparing the berry flavor to? Do they actually have no flavor at all?

Did the plant come with a tag stating the variety, or did it just say "thornless".

Do you have local farmer's markets that are selling more flavorful berries? That would indicate that you would have a chance of growing flavorful ones since you would have similar growing conditions to them.

In general, flavor does not depend on having a thorny variety.

After growing thornless blackberries for four years taste is not my biggest problem. In fact I feel like they taste better than the wild ones near me. Just like apples some varieties are sweeter than others. Pick specific varieties such as Natchez or Triple Crown. Good Luck, Bill

Larry they are just called "thornless" . I'm actually comparing them to some I had at my house in Ramona that had been planted 20 years ago and have since grown wild over in the adjoining field. They were so yummy. I'm about 20 miles away but the climate is identical. I'm going to repot in garden soil with compost and worm castings. Maybe that will help as the soil is very sandy in the pot they are in.

Repotting is one possibility, and getting some of the wild field plants is another--but perhaps those are thorny.

Let them ripen longer and see if the flavor improves. I'm guilty of picking berries too early and not getting the flavor I'm expecting. Just because the berry turns black / purple doesn't mean it has ripened.

My Navaho and Triple Crown have a great taste when ripe. My Doyle and Chester however do not. I find them quite bland in comparison.

Thanks everyone! I am going to repot them. But I think I may go harvest some cuttings from the bushes up in Ramona too. They are thorny, but oh so worth it!