Back when I was more naive I planted a plum tree pretty close to a raised bed where I grow vegetables. Now that the plum tree is close to full size I noted the veggies in the raised bed had very little vigour despite using fertilizer. I can see now that one bed is full of plum tree roots, which would also explain the plum tree’s hyperactive growth this year. In retrospect I should have put 2 and 2 together sooner. I removed most of the roots in the bed but I was nervous doing so because I’m not sure how harmful it will be to the plum tree. Given the tree size and placement of the bed, I’d estimate about five percent of the tree’s roots were removed, maybe a bit more.
I would prefer not to remove the raised bed, or the tree for that matter. I don’t have a lot of space and by necessity things are a bit crowded in my yard. I also feel like it’s probably not a good idea to douse the tree with too much fertilizer every year. Anyway curious if others have experienced the same problem (if you removed the roots from the raised bed), and if the tree came out alright.
Removing 5% of a trees roots won’t hurt the tree. You could remove half, especially while dormant, with no long term damage.
Ideally you’d isolate the tree’s roots from the raised bed. Would it be possible to remove the soil from the raised bed and then line it with a root barrier? That might be a bit tricky because any drainage holes are entry for plum or other roots. Maybe you could turn the raised bed into essentially a big pot with drainage but then an air gap below to discourage roots.
I had to put my raised bed on an airlayer to isolate the raspberries fro the adjacent cedar tree roots that were invading my bed. You made want to consider doing a similar project. I used bricks spaced about 2’ apart to support metal roofing as the floor of my raspberry beds which are supported on the perimeter by 2”x6” boards. The cedar roots will not grow thru air so this is one solution if you do not wish to related your raised bed.
Dennis
Kent, wa