topsoil laid on top of clay

[katostan]

I recently laid a 25sq.metre veg plot with blended loam topsoil. The area had been dug out previously by me for a patio area, but we decided it would make a nice veg plot instead. The base was solid clay. My wife Linda goes to an organic gardening course at Leicester Eco House, and they say that we should have dug the topsoil into the clay. Do I now have to do that very thing or just plant as is? Suggestions very welcome as the clay is not easy to dig in as it is like modelling clay - very solid and difficult to break down to mix with topsoil.

[Cheezy]

Depends how deep the top soil is, and what veg your going to want to grow. Ie any root crop is going to need at least a spades depth to grow in.

I wouldn't grow anything thats in perminently, as the clay will act as a pan and stop root growth down wards.

You could make raised beds to allow a greater depth. You could heavily lime the soil, as this will help to start break up the clay. A long with lots of organic matter.

It all depends on the depth of the top soil.

[wulf]

If you want to be scientific (and a bit lazy) you could dig the top soil in for part of it. Plant your crops across the divide and observe if there is any difference between the two parts.

Wulf

[Annpan]

This is by no way advice, more a secondary question...

Could you dig out small bits of the clay (say, a plug a spade width by a spades with) then fill the hole with organic matter. and do that every 2 foot.
When you come to plant it up in the spring it would be much easier to dig it all through as you would have some help from the frosts working on the organic matter.


Or am I talking complete drivel?

[Magpie]

My soil is naturally topsoil on clay, with no trouble - all clay soils would end up with topsoil eventually, so I don't see a problem with it.

I definately wouldn't dig the clay - it just makes it worse, and you'd end up with lumps of clay in your nice topsoil. Your topsoil will naturally deepen with time, as you add more organic matter, too.

Maybe just plant crops that aren't going to go deeper than the depth of your topsoil, and maybe plant spuds - I find they help almost all problems of soil texture to start with. They send out thin stems underground, which swell into the tubers, so help break up heavy soil such as clay.

[Millymollymandy]

I'd do my best to break up the clay or another summer like last and you will have very waterlogged veggies.

[frozenthunderbolt]

Plant chicory and other very deep rooted plants and they will drill down into the clay with their roots then when they die the roots rot out and extend the organic matter further down into the substrate while helping to break up the clay.
Maybe a mixture of chicory and mustard and a deep and shallow green manure when you dont have food crops growing. or else devide it into sections and plant them in rotation. probably better like that as chicory takes at least a full season and will grow longer in good conditions i believe.

Far easier than removing the top soil and hireing a *Heavy Duty* rototiller to break up the clay and intergrate gypsum and orcanic matter, both of which help recondition clay. :-)

Ide say keep adding mulch, compost and organic matter on top and consider also buying some good gardenworms to release into your plot - they will pull organic matter down at least a foot and will help make inroads into the clay.

Hope that helps Jed.