Rocky, gravelly, compacted soil

Hi all,

At the side of my how which gets the most sun and is the best location for a perennial garden, about half of the soil is a complete mess. It is still soil but only barely. It's possible that it may have been a driveway 25 years ago, it's hard to tell. Anyway, it's very compacted, and probably consists of 50% to 75% small stones and broken shale. It's like this down to at the very least 8 inches. With summer weather basically here, the grass over a lot of this area has started to go brown, so that's not a good sign. I realized how much of the yard was like this when I dug a couple small holes for a soil test.

So here's my question. I understand the benefits of deep, sheet mulching for building soil. I want to know if there is anything I should do to the ground before laying down a ton of organic matter. It seems like the small amount of top soil this will add won't be enough, and the rocks will be a root barrier. Should I import topsoil? Should I rototill the heck out of it before mulching? Any other ideas?

Thanks,
Dave

Hi Decev,
Paul talks about this in his recent podcast 026 http://www.richsoil.com/permaculture/263-podcast-026-listener-permaculture-questions/ , maybe 1/2way through the recording?
Good luck!

You want to have a perennial garden but an annual too. Or you might not have potatoes, tomatoes and all these nice vegetables. Annual vegetables are those who need the most sun and there are loads of perennials which can do with less sun. If you put the annual vegetable garden there you still have to hoe all the stones out but not as deep. you might think of huegelculture. Most annuals will do in a soil not deeper than 35 cm.
I would get a good garden mattock and start hoeing. If you find bigger stones they are great for building walls etc.

Thanks for the replies! I hadn't listened to that podcast yet, thanks for the tip. I think I'm likely to rent a roto tiller this one time to break up all of this junk on top before using standard PC practices to improve the soil.

I will eventually plant annuals here too! But for now I already have a garden, and I'm just worried about getting in the stuff that will take a long time to grow, like trees and shrubs. I've been told the best time to plant a tree is last year. I guess I'll just start digging the hole for the first tree and see what I find down there.

there is a book out by Patricia Thorpe called the American Weekend Garden where she does gravel gardensm, quite interesting

a lot of things will grow quite well in gravel, but loosening it and amending it makes total sense

a pitchfork might help in loosening it stick it in and wiggle it back and forth standing on it..

i have had some gravel areas and they tend to love to grow things once they get established

We have tons of rocks and have lived in places with a gravel yard.  It all depends on what plants you want to grow.  Some will do very fine in fact better in rocky hard ground.  Some will die.   Some plants will work almost like a tiller with strong roots.  But they will never be able to pick up the rocks and move them.

I would not be afraid to till the heck out of it.  Till and till and till! Then maybe double dig with a crow bar?  Depends on what you want to grow.   I know a lot of people say the no till method is best and I understand that.  However to break up the hard crusty ground with a machine is not going to destroy anything. I feel it can only help the situation.  Plant roots will not grow into the rock.  You can till in peat or grass clippings maybe some sand what ever you think it needs.  You may even till next year too.  After you get the soil in the direction you want it to go then stop tilling.  When you see worms or weeds life signs stop.   

Word of caution know what you are getting for sure if you purchase top soil compost manure what ever. I didn't make double sure and lost 2 years of garden time and am having to start over in a new location.  Purchased  contaminated stuff. 

In heavy gravel soils, I would suggest a good roto-till, and then shovel the soil on a frame of 1/2" or 3/8" hardware cloth to separate the dirt from the rocks.  Then add compost to the sifted soil.  Root crops such as carrots, radishes, potatoes, etc will be malformed if grown in rocky soils.  Good roots are needed for any plant, but it should be obvious that a root crop is particularly dependent on good roots.

(Save the sifted gravel for whatever purpose...concrete mixes, pathways, tire rut filing on roads/driveways, etc.)

I'm having literally the exact same problem. Already have a place for annuals (and that place is the gopher free yard) and need to get some trees in the ground! Some of the ground is ok, but I was clearing spots for specific trees and when I go to dig a hole for my cherimoya tree today I seriously could not get the shovel in more than 2"... Yes, 2". I don't know what to do other than not planting there for the time being, but then I have to put the trees somewhere less optimal... Terrible situation.

Here are a couple of ideas:

1) use a 3 or 4 foot piece of rebar and look for cracks in the rocks that go deep.  These are good places to plant hardy trees or bushes.  You may need to wait until after a heavy rain for the shale to soften.

2) With a hammer drill or jack hammer break out the rock and move it to  a border, replacing it with fine soil.

3) Plant cactus

Just wanted to say here that I used John Polk's advice here with great success so far.  I used 1/2 inch hardware cloth. I planted 6 small seedlings in the area and got about 20 gallons of shale for my trouble. I think if I used any tighter cloth I'd run out of soil! I'm going to rototill the rest out of there in sections. There's about 700 or 800 square feet like this that I want to cultivate. That doesn't sound like a lot, but doing all of this manually is going to take forever. The 20 gallons of shale came from maybe 10 square feet. This should be fun

No idea what I'm going to do with the shale. Half of this area is shale and smells like a stream when you dig it up, I think there is a seam of this running through the yard. The other half is gravel just like you'd use in the driveway, and I do think this area must have previously been a driveway. I can probably find a use for this stuff.

I can identify!  I've been digging out a rocky area beside the house for my kitchen garden.  Many buckets of rocks, probably several tons by now.    And I'm only halfway done with about 1000 square feet.    I've been replacing the rocks with logs, making sunken "hugel" beds.

Many rocks used as a border on the downhill side: