I think they actually sell agricultural fabric and plastics with the express purpose of doing that but it's been so long since I put one in the raised bed that I cannot recall. With raspberries they won't spread as fast as mint, so no worries, but you shouldn't have to worry about it taking over the garden. I planted one in the ground and had it there for about 5 years. It grew to a nice size, produced nice fruit, but it started getting out of hand so I had to remove it. Then for the next several years I had to walk very carefully there (I like to be barefoot) as new plants kept popping up. In the end I had to dig out about 4 feet square and 3 feet down just to make sure I got every last bit of root.

I would like to have some of your raspberry plants if you still have some. Thanks Lee

For flavor, Cherokee is my favorite. Other good blackberry varieties that have thorns are Brazos, Kiowa and Rosborough. Thornless varieties that do well here are Arapaho, Apache, Quachita and Navaho. For anyone who has not grown berries and wonders what the difference is, the thorny blackberries tend to be higher producers. That makes up for them being harder to pick. There's a relatively new development in the blackberry world that involves varieties developed to produce fruit on the current year's growth. Traditionally, blackberries produce berries in summer on the previous year's growth, called primocanes. Three of the new varieties that produce on the current year's growth are Prime-Jim, Prime-Jam and Prime-Ark 45. I have not grown any of them, but may plant some of them in a trial planting next year. Blackberries, whether they are thorny or thornless get about 5' tall and need something to lean against, if not a trellis, then at least a fence or wall. My brother grew them along the west wall of his house. He enriched the soil really well with lots of cow manure and they grew and produced like gangbusters. I've seen them grown along fencelines, planted about 3' or 4' away from the fence, and I've seen them grown on trellises. If you don't support them, they have trouble staying upright but they're happy leaning against a fence or wall if you don't put up a trellis.

Next year start getting them outside as soon as temperatures allow it, 2C and above they will live and be better prepared to handle the unexpected light frost and strong winds. Of course you'll have to bring them back in for the night. Not meaning to start an argument but big plants do not equal (much) earlier production. I put some of mine (1ft or taller lots of leaves) in my in-law's yard next to his (sickly looking 6" 4-6 true leaves) right after Vic. Day. You could see the difference immediately but now mine look to have lost the advantage (may still be a week ahead of his). We'll see about ripe toms but i'm expecting them to come about the same time judging by the state of the plants right now(other than a few of the early varieties i planted in his yard)