We have wild blackberries here also, and with all the rain, they are really filling out with berries this year. I want to transplant some also, and the reason for that is the weather uncertainty. Last year when we moved here, it had been so hot and dry that the berries started to ripen, and then all just dried up before they got ready to be picked, so we only gathered a few of them.
This year, there should be plenty, but if we plant some closer to the house, then when it is a dry year like last year, we can water them if necessary, and have a good crop regardless of the rain, or lack of it.