Improving Clay soil - digging subsoil?

bogfire

I want to grow potatoes in my new garden. Digging reveals a layer of about 6 to 8 inches of heavy clay soil, then a thin crusty red layer and then a light grey clay layer. I want to improve the soil and will be adding compost and leaf mold and finally manure.

My questions -
Should I dig up some of the layers under the top clay soil and work this also? (Maybe it is best left alone and concentrate of adding material to the top clay layer.)
What is the red layer - some kind of iron?
What depth of material for potato growth should I be targeting

Thanks for taking time to help me with this.

redser7

I wouldn't bring the subsoil to the surface. How much land are you planning to cultivate? Sounds like raised beds might be of benefit to you. Just work with the topsoil you have and continue to amend it with co post, manure, leaf mold, green manure etc. some people find it handy to just throw organic material on to the surface and build it up that way. Throw weeds and grass clippings on too. It's all good. Conditions the soil and raises the fertility.

redser7

You should have plenty depth there for spuds. I usually put mine relatively deep at 8 inches. Just earth up by adding grass clippings, cardboard, straw, whatever is at hand, on top of the soil once the haulms break through.

bogfire

Thanks guys, appreciate your inputs

Sgt Pepper 64

redser7 wrote: »

I wouldn't bring the subsoil to the surface. How much land are you planning to cultivate? Sounds like raised beds might be of benefit to you. Just work with the topsoil you have and continue to amend it with co post, manure, leaf mold, green manure etc. some people find it handy to just throw organic material on to the surface and build it up that way. Throw weeds and grass clippings on too. It's all good. Conditions the soil and raises the fertility.

I'd be a bit careful with weeds. Some like Bind weed take a lot of heat to kill them.
Annuals are deffo ok, but watch some of the Perennial ones

redser7

Very true. Might be an idea to keep a bucket of water and throw them in there. Weeds can be full of nutrients. Let them fester in there a bit and then chuck them on, or else make a tea out of them.