Ray Newstead's EarthTainer design for self-watering containers would work great for blackberries, raspberries, and blueberries. Even the upright thornless blackberries can benefit from support unless you keep them headed back to 3 feet tall.

The tomato cages in Ray's design will work fine to provide support for the blackberry canes. I'm using tomato cages to support some blackberries and raspberries I planted this spring, and it's working great so far. After the canes get started you don't see the tomato cage hardly at all because heavy growth.

I've grown climbing roses in containers using tomato cages for many years. They are quite pretty when the canes come out of the top and then droop down into a fountain shape. It sort of reminds me a small version of the "Rebar Bougainvillea Trees" at the Getty Center.

With 3 of the EarthTainers holding 2 plants each, you should easily get 20 - 25 quarts of berries. In zone 6 you need to make sure you get varieties that are very cold hardy. Growing them in containers will allow the roots to freeze as they might not if planted in the ground, so I would go for a zone lower than yours when planting in containers.

Everbearing raspberries like "Autumn Britten" , "Encore", and "Heritage" will give you both a spring and fall harvest. Some are hardy even in zone 3. There are some cold hardy blackberries, but as a general rule raspberries will be a bit more tolerant of the cold. On your patio make sure you are getting thornless or nearly thornless. Some of the raspberries, like "Autumn Britten" are almost thornless. On the main stalk they have stubby little short spines that are not any problem at all. When ordering the selection of plants I got this spring, I failed to notice that one of the ones I ordered is a really thorny one. It is like dealing with a cactus. I have a strong feeling that after it bears fruit next spring, I am going to throw it out unless its fruit is really something grand.

By planting more than one variety and picking ones with staggered fruiting seasons, you can greatly extend your fruiting time rather than getting 10 gallons of berries to eat in a single week. With 6 different kinds, you could have an entire month in the summer and another month in the fall from the plants.

Blueberries are excellent in containers as well, with a wide range for any size container or space.

gtippitt,

Thanks so much for your response. I was actually almost giving up on the idea...as the more I read, I got concerned about the survivability of blackberry plants, during the winter, in containers.

I'm glad you mentioned blueberries. I'm trying to find room for more of them, as well. We planted 3 bushes, about 3 years ago. One died right away. Of the two remaining, one did produce (for the birds) this year. The other is still rather small. I have to readup on care for these. We did not container these...but our soil is mostly clay. I'm trying to get enough blueberry bushes to produce about 50 quarts. We typically go U-pick every year...and freeze up a bunch. Since I was thinking of giving up on the blackberries on the deck....some of my prime blueberry space was being eyed. It is so hard to plan all this out. I'll look at this Earthtainer idea. That might help me out...letting me retain the prime space by my shed, for the blueberries.

Kwilliam, since you are in zone 6, you will have to keep your containers under cover for winter (attached shed or maybe even well-protected under your deck?). I have had success with storing my container blueberries and raspberries in my shed from November until the end of March/beginning of April (depending on the spring weather). It helps if they are raised off the cement floor, if that's what you have.
Good luck.
Judith

Judith,

What do you do for watering during the winter?

Thanks,

Keith

I throw a shovelful of snow over the pots every few weeks. Even though they are in the shed, the soil freezes solid, so I don't worry much about moisture. A couple of years ago, we had record amounts of snow here, and the shed was completely snowed in - no way was I going to shovel away that mountain in front of the door! Anyway, they went 2 months or more with no attention, and they were all fine. You are in a warmer zone than me, so you may have to check on them more often. Just don't let them dry out if they do thaw out.
If you do decide to leave them outside because your containers are so big, then I think you'll have to do a lot of protecting (wrapping with burlap & filling it with leaves, etc), especially the blueberries and blackberries, which are less hardy than raspberries.

Judith