Is it a domestic blackberry bush, or wild blackberries?
If its wild, they get no bigger than a stawberry plant.
If its domestic... it will destroy everything, they can grow well over an inch a day and will multiply as well as take over your whole garden and even your whole front yard if you dont keep them under check.
I'm not bluffing, after living on a dairy farm that got taken over by them in under a few years, blackberries are delicious but.... the plants themselves are a nuisance. If you are planning to keep care of the plant and and keep it in check, your going to have to do it daily, chop off a branch and it will grow back in days. Its crazy.
Ill see if I can find a picture for you,
They will grow that big in little over a year at the least.
Another note, if it's not doing well, I'm suprised, they live like weeds. If your still going to grow it then give them A LOT of water. Note that they thrive in western Washington where it rains 5 days out of the week year-round.
· 1 decade ago