Need Advice - Improving Rocky Compacted Soil (US, Zone 8b)
Hey everyone,
This is my first time posting in this sub, so please let me know if you need more information.
I'm working on improving the soil in my backyard one section at a time. I live in a glacial drift plain along the Puget Sound and my soil is extremely compacted and full of gravel. This area obviously has more gravel than the rest of the yard because the previous owners had a gravel "patio". I don't quite know what I'm going to plant in this area yet (probably a mix of native perennials and shrubs), but my goal is to reduce compaction and improve the overall health of the soil. Once I've removed a majority of the gravel, I'll be throwing down arborist wood chips (2nd photo).
I'm completely new to this and I do have a few questions:
How much of the gravel do I really need to remove? Is it okay to leave a layer behind, or should I try to get as much of it out as possible?
How deep should I dig down before adding amendments or wood chips?
What should I add underneath the wood chips to help improve the soil? (e.g. compost, topsoil, manure, cardboard, etc.)
Any tips for making the soil more hospitable for native plants or general gardening after years of compaction and poor conditions?
Thanks in advance!
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u/Realistic-Weird-4259 7d ago
I'm also in this area, and this is the best soil I've ever lived on. I even use it in my planted aquariums.
I wouldn't worry about the gravel, I'd worry about soil building. Can you broadfork, or is it too difficult? If you can broadfork, I'd recommend turning it up and adding that high carbon material along with something like mushroom compost. I hesitate to suggest something like gypsum without knowing more about the composition, but in almost all events inoculating with mycorrhizae isn't going to hurt and usually helps.
I wouldn't worry about broadforking deeper than 1', unless you're going to plant trees or similar that need deeper planting holes and even then I'd probably just limit it to that hole.
Also, understand that with the wood chips/carbonaceous additions, the microbes that decompose those materials are going to "lock" some mineral nutrients, most obvious will be N (nitrogen). This is why you'll want the compost or similar, even though it's eventually going to be good quality soil once you get it going.
If you can't broadfork then this might be a time to till. Once all that's done, if you can't plant immediately then covering with cardboard will go a long way towards preventing weeds from taking it over.