Blackberry canes grow huge but no fruit!

Question

I am worried about my blackberry shrub, not sure whether it is diseased or what. The new tall portion is like last year, even bigger, 6’ or more, straight up like a tree. It looks fine. But the older canes that lean over are strange, they had some blooms this spring but have turned brown and only produced a few small berries. In 2018 I blamed Jap beetles, which came out worse than anything I’d ever seen and feasted on everything including the berries. But even at best I only had a few handfuls then. This shrub is 2 years old I think. Seems like if it were diseased the entire shrub would look bad. But as I say, the tall portion looks OK. In my zone this year, we had a VERY wet and chilly spring and early summer. But around the first of July the rain stopped and these past few weeks have been very hot, scalding hot at times. Now it is cooler again and we have gotten some rain. But many years ago my mother and I had 2 large healthy shrubs and tons of berries during the most fruitful seasons. The weather didn’t faze them then. 2012 brought record breaking heat to us, which may have helped to kill the shrubs which were getting quite old. All that remains is a small piece struggling to return. That was why I decided to begin over again with a new plant. I’m beginning to think I shouldn’t have bothered. I wonder if I did something wrong. Pruning at the wrong times? My lawn mowing guy clipping off the ends of canes in his way? A need for fertilizer and mulch? What can I do to fix this problem? Photos added below.

Answer 1

Yes, you should prune twice a year: tip prune in the spring to encourage branching, then after fruiting ends, cut down the canes that fruited; they won’t fruit again. It takes 2 years for canes to fruit, so you are just getting started. Also, you might remove some of the competing vegetation at the base of the plants. I also would get a soil test to see what nutrients the soil might need. Contact your local Extension office for that.

Here are the pruning tips:
https://www.gardeningknowhow.com/edible/fruits/blackberries/blackberry-pruning.htm

https://www.gardeningknowhow.com/edible/fruits/blackberries/blackberries-not-fruiting.htm

https://www.gardeningknowhow.com/edible/fruits/blackberries/growing-blackberry-bushes.htm