Q.Why Are My Blackberry Plants Not Growing Canes?
I purchased thornless blackberries several years ago and they just don’t grow any canes for berries. At best the plants 6″ high. I conditioned the soil when planted and keep them watered in the hot summer. Soil drains well. They just stay close to the ground. What can I do to have them grow upwards and produce fruit?

Certified GKH Gardening Expert
This could be an overall set of nutrient deficiencies, or pH imbalance. I would recommend testing the soil for nutrient and pH deficiencies and amend accordingly. These articles will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/special/organic/the-importance-of-soil-for-an-organic-garden.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/improving-garden-soil.htm
https://www.gardeningknowhow.com/edible/fruits/blackberries/growing-blackberry-bushes.htm