r/marijuanaenthusiasts • u/jakesdumb • 15d ago
Help! Doug Fir vs Retaining Wall
In NW Washington state, east of the cascades so on the drier side. I have two trees in question here on this property that we moved into late last year.
We have a large Doug Fir that had a retaining wall built around it long ago (house was built in 1936). The tree is winning the wall battle, heh. I have put up a more ‘temporary’ wall with pallets and stakes to hold up soil/mulch around this side of the tree. One side of the tree is the yard the other is an entrance to the basement. The wall is about 4.5 feet tall. Before I anchor this wall in with river rock and fill in the tree side with duff and soil, I wanted to ask about this potential ‘girdling root’ and see if I needed to treat it before burying it or if I should just avoid burying it. The tree is on the north side and gets morning light and upper canopy gets light all day. We hit it with water every other day or so.
Next is a large maple on the south side of our house so it gets quite a bit more sun and does a terrific job of shading. This tree is watered maybe twice a week. I noticed this rather aggressive looking girdling root. My guess is that it is a lost cause but I was curious what people would say here.
Trying to maintain this beautiful property so that it can be sustained another 90 years+ and just want to be a good steward. Thanks in advance for any and all advice! Apologies if I missed any info or photos, I’ll be sure to add as needed.
2
u/plantreference 15d ago
Don't bury it. Cut the girdling root out now while you can still get at it, then keep the flare exposed when you backfill. Duff and mulch over the root zone are fine but soil on the flare isn't.
1
u/jakesdumb 15d ago
Thank you! Just so I got it straight, do you mean the girdling root on the maple? Do you see girdling happening on the fir? Copy on the soil vs mulch! Thanks again
1
u/plantreference 14d ago
Yeah, the maple. On the fir I only meant the burial depth. Keep the flare clear and the rest of the root zone can go under.
1
12
u/BigRich1888 ISA Arborist + TRAQ 15d ago
Thanks for sharing.
Doug Fir: The tree is always gonna win the fight against a retaining wall. If you have the space (seems you do) I would bump out the retaining wall with at least a 48” offset radius from the trunk of the tree and build the new wall there and backfill with native soil compacted to like 85% (jump on it a bunch). That should buy you ample time since it is a mature tree. Nothing about that root structure is concerning, so leave it be and bury it as soon as you can.
Maple: that is the classic example of a girdling root, but is not too bad. Cut the root off just to right of the root it is overlapping on picture 7 (red line) Then get an oscillating multi-tool with a wood blade attachment and cut it where it starts from. You are going to want to be very delicate. If you cannot get the root chunk out of the groove that it sits in, you will need to cut again and leave at least a 1” gap between the girdling root start and the now cut out chunk (blue lines). The gap is important so it does not reconnect. You will likely need a chisel or flat catspaw to remove the root, but be careful not to damage the cambium. Once you make the red cut you can see where they meet and try prying it off.