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@makinstuff

I hope so too, I would say give the plant a tug from its stem.. If it easily pulls out from the dirt the roots arent ready.. But if you tug and all of the dirt tried to come with it then you probably have enough.. Also vigorous plants, like cannabis will start to grow the roots through the drainage holes in the container making it easy to see its rooting. Blackberries Im not sure, but giving them a tug should tell.