My DH and I want to put a retaining wall in our slightly sloping backyard and fill it in some to level it out. We have some trees (pines and oaks) that we need to accomodate? How close can we get to the trees without hurting them?
Thanks so much!
Edited to add that we're planning to fill the area in with about 15 inches of crushed limestone and then 6-8 inches of organic matter on top of that. How much can we put on the ground near the trees without it being a really bad thing?
That's what we are wanting to know. Can we fill in around the tree to put the retaining wall below the tree on the slope? If so how much fill can we put around the tree with out killing. If not how close to the tree can we get. I vaguely remember someone saying you could put 6-8" of topsoil on the base of the tree, but im not sure.
That depends on the trees. Trees that develop top roots NEED those roots exposed or they suffocate. You can gradually pile on an inch or two of soil at a time and the roots will go ahead and grow through to the surface again, but if you just cover or bury them, they'll die. You could probably cover just part of them and it would be okay. I would keep the wall just at or outside the drip line of the tree for best results, and maybe put in some soil sulpher to counteract the limstone effect.
Trees should be no closer than 10 feet from a structure, generally. Water will be the worst enemy to the trunk if you pile soil up around it. The soil will retain moisure.
How about some nice serpentine curves in that wall that will avoid the actual trees?
Be kind to your trees, and when in doubt about something like this talk to a local garden center, county extension, or tree service. People love to talk shop and getting several opinions from various pros in your climate zone is well worth it.
We just had a 80-100 year old spruce die last summer and we had it taken out last week. So sad. The up side? Our hazelnut tree will now thrive, and the tree service guys (who are loggers and foresters) gave me some GREAT advice as to how to care for the surviving tree. They were telling me to mulch, fertilize, and water out to the drip line (the edge of the canopy). That is the area that needs attention when caring for a mature tree.
Again, make a couple calls and get some local people's input. I would hate to see something happen to your pines and oaks. Last week was tough seeing our old man tree get cut down. Good luck!
There's an Oak Tree Foundation here in California that has a newsletter, and a website with lots of info on oaks. I don't know if this info totally applies to your type of oak, but reading this info is a starting point. Then I'd contact a local Native Plant Society, or some professional Arborists who know the specifics about your type of trees....
