@Natalie,
I’m having the exact opposite experience with raspberries as you—I can’t get them to grow enough!
Like you I love raspberries but this is year 3 for mine and they are just sad. The ground is just too heavy and they really aren't expanding much at all. I get a few berries but not nearly as much as I should.
Ironically the same solution may work for both of us: buckets! I can put soil that they’ll like in the buckets and sounds like they’ll be happy. I’m not sure about any long-term issues that could come up, but it’s worth a try because I am determined to have raspberries!
A side bonus is I can move them somewhere else. Right now they are in real estate that I could be using for daylilies. Precious, precious real estate…