I am the proud caretaker of a 100+ year-old Southern Magnolia - she's huge! There is a large brick patio, laid in sand, on one side of her. After about 15 years, some of her surface roots are beginning to dangerously upheave the bricks. Can I cut away the offenders?
Maybe you could get away with this but since the magnolia seems to be a valued heritage tree I wouldn't. Part of the advantage of bricks set in sand is that they can, in fact, move up and down with frost (or move up with roots) instead of cracking like concrete. It may be possible to raise the whole surface up to a new, higher level to accommodate the tree.
I agree with Ron, leave the roots alone if possible. Perhaps removing a few bricks and backfilling with sand that can be tamped relatively densely may be an option?
HELLO! I appreciate the responses. Unfortunately, the patio is as raised as much as it can be, and this is an area very much used for family gatherings. The reason I even considered cutting the roots is because an arborist told me several years ago that the roots of this tree probrably go for blocks, and the house could blow away before that tree ever moved. So I thought maybe there are enough roots to sustain it. The roots around her base really are numerous, and huge. I have to plant hostas where I can...not where I want! The roots I need to amend are at least 15'-20" away from the base. THANKS!
Being the custodian of such a tree is not an unmixed blessing. There are compromises to be made. Given that you are the person who has to make the compromises, the right question to ask tree experts is probably not "should I cut" or "can I cut" but rather: "what will happen if I cut this much root on this tree?" As the person trying to co-occupy the space with the tree, only you can decide whether the risk to the tree is worth the benefit you seek to gain. If it's a choice between - say - the tree maybe having slightly smaller leaves for a year before it recovers, and having your kids or your grandma trip over raised bricks and break their noses and knock their teeth out, that is a value judgement only you can make. Tree experts know trees, but they don't know your family and they won't be there to wipe up the blood. By the way, if this is an urban area and the roots go on for blocks, I'd bet that the roots have sustained some injury somewhere along their length quite regularly. EDIT: having said all this, and suggesting that it might be OK to cut the roots, I suspect that the cut ends of roots will re-grow more roots, which will always heave the patio. There is probably no permanent solution... other than tree removal, or changing the location of the patio.
