I have a rose bush that is in a wine barrel planter. The planter is breaking apart and I think the roots of the rose bush are now growing into the ground. How can I successfully re-pot it or transplant it into the ground?
Depends what you mean by 'ground'. If you mean paving with gaps or cracks in between,and the rose roots have gone down the gaps via the drainage holes in the barrel (a not uncommon occurrence), other than breaking up the paving and digging out the roots, then replacing the paving, all you can do is cut the roots off and hope the plant survives. If though, you mean the barrel was stood on soil, then dig out the roots that have grown through and into it and then transplant.
When you decide to deal with the situation, before you do anything else, remove any loose soil and the remains of the barrel, and clear away any excess soil at the base so you can see where the roots have gone. It's best to transfer the rose into the ground if you have a suitable spot for it - roses prefer to be able to put down deep roots.
This problem occurs quite often, so I've had to deal with it on several occasions, with varying degrees of success. Of the two roses I had to deal with, both survived the loss of root material,but neither rose bush was particularly large or tall.
Plants are far hardier than most understand. I would easily and without hesitation, dump the barrel over, break off all the roots coming out of the pot, pound on the pot a bit with my foot and gently pull the entire plant and its root ball out of the pot.
Leave it on its side. Laying a tarp down really makes this process easier and fast to clean up.
Have your new and slightly larger pot (3" larger in diameter?) ready with maybe a third of the pot filled with fresh potting soil (no moisture gimmicks like sponges or gels and no added fertilizer), wet that soil, shake it to firm, plant your rose, pulling the roots a bit from the root ball, hold it upright as you fill with more potting soil. Firming all of the time...keep the graft above the soil surface (talk about that in a bit). Leave at least a 1 to 1 1/2 inch gap between rim of pot and surface of soil. Water, allow to drain and you are done for a few weeks.
Need to know more information such as what you do for fertilizer, how you water, where exactly you live and the micro-environment of your potted rose...how much light, how long has it been there and certainly a few pictures of your rose! Feel free to RIP all those roots coming out of the bottom. Won't hurt your rose one little bit. In fact, a little rough stuff working on the roots will activate more growth. Commercially planting thousands and thousands of plants over decades throughout all seasons to include slicing and butterflying the root balls...heck not one single plant died. And my guys did most of the planting...'get 'r done'! Not a single plant has ever died.
Please send pictures before doing anything. Well, you can go get a slightly larger pot, I'd get clay IF you don't have to worry about freezes. Sand cast concrete in dove gray if you do have freezes. Bury pot if you are below Zone 4. Or wrap with burlap and non LED christmas tree lights...lots of questions.