Hi everyone!
I set up a garden on my roof last fall, so this past summer was my first summer with it. Some things did well, others did not. My questions for you are regarding something that did not do so well; berries. To preface this, I will mention that I had planted raspberry, boysenberry, blackberry, strawberry, gooseberry and tayberry (blackberry x raspberry cross) in wooden bushel buckets last fall. The strawberries and raspberries had produced the previous summer, and I transplanted them. The rest I purchased from a farm and were inactive. When spring came along, only the gooseberry and the raspberry came out of dormancy. The gooseberry was fine, but the raspberry was barely alive, came out of dormancy late, and only growing leaves where the plant meets the soil (ie. the branches were dead).
I know all these berry plants are prolific growers in much colder regions of Canada than Toronto, so the issue is not that they cannot survive the cold, however because they were in a container, the soil likely froze, killing the roots. Now, I have two options to prevent history from repeating itself;
1) Build raised beds (I've already built a dozen on my roof, so one more won't make a difference, if so do you think would 6' x 3' be large enough for the 5 rubus plants, 2'x3' for the gooseberry, and 2'x2' for the strawberry?)
2) Insulate them somehow
What are your thoughts? Thanks!