I'm in 7A (western NC). I just don't want to get them stimulated to grow with the improved soil...

I heard they can grow roots during winter...but I'm not sure that's true and I'm not sure if it's worth disturbing the plants for a possible boost in root growth.

Improved soil? Are you amending the planting holes? If so that's a no no. Plant your canes in the native soil. If the ground isn't frozen go ahead.

In colder zones winter planting can be an issue because the frost heaves but zone 7 it’s not an issue. Also your plants will be happier being stored in the ground for winter than wherever you have them now

floral_uk---what's wrong with amending the soil??

This paper is a good place to start, Ann https://s3.wp.wsu.edu/uploads/sites/403/2015/03/soil-amendments.pdf

Floral UK, thanks for this article. Thankfully, I've been gardening a very long time and I've already thought through each point over the past years of gardening. I basically dig $500 holes for my $5 plants. That's why is takes me so long!!! :)

The biggest point (creating an amended soil/native soil interface) has been addressed. At the end it says "In extreme cases, replace the entire planting site with topsoil." This is basically what I'm doing. I'm planting rows of black raspberries 3 feet apart and blackberries 4 feet apart, but essentially I've amended the entire rows, 3 or 4' wide and 30' long. That SHOULD allow the roots plenty of space to spread out. (And it's actually pairs of rows, so the black raspberry row is 6' wide, blackberry row is 8' wide.) My biggest concern has been the bathtub effect as described in that article; my soil turns to sludge when it rains and the water takes forever to drain. There is no air in my native soil at all. I can't imagine anything doing well in my native soil! My fond hope is that the water will sink to the bottom of my trenches and allow the roots to breathe in the amended soil. I am also putting in soaker hoses covered in thick mulch, so I can keep them damp during the dry season.

I know my planting sites sink over time, so I start them slightly raised, and add compost when/if they sink.

I really appreciate this article---thank you for sending it! It will help to keep me on my toes and continue suffering through the gigantic planting holes!