I am guessing your asking about your blackberry bush,you could try growing it in a pot and trailing it along a fence but i prefer the ground trained along a fence or wire.make sure you give it room and the right space and prune in spring.
A blackberry is a very large and strong growing plant. Mine will throw out 30ft canes if I let it. You have no option but to plant it in the ground. They require a lot of space and ideally horizontal wires to support the canes. Every year the old canes are cut out and the new canes tied in. One of mine is helping to hide a shed and is very strong and with lethal prickles. A nightmare to be honest, but it crops really heavily. The thornless ones are much easier to manage and not usually so vigorous.
I have a blackberry black bute,which is a very large fruit and delicious berrys,last year I collected nearly 3lbs of fruit,being thornless makes it easier yo pick,just cut all old fruiting canes out every year,and feed a top dressing of well rotted manure or compost. It has a spread of upto 4 mts,so horizontal wires are required to tie the canes to,
Blackberries easily grow. They can be everywhere if left unattended for a long period of time simply because they have a good survival rate. They tend to creep around so be sure to plant them with fences if you don't want them all over the house. Taking care of blackberries are one of the easiest. You just need to water them usually once for regular season and twice if the season is really dry. - Jeanne
I agree with others - get it in the ground where it will grow much better. They are one of the easiest and most trouble free fruit plants you can grow.