Can i mix topsoil and clay?

Mark Dunn

Hello, I'm new to this forum and this is my first post.

I am trying to make a useable garden out of a steep hill.

The garden is 10m wide and 20m long and rises up 5m from the house to the back fence.

I have dug out a small patio at the back of the house then built 2 tiered beds with a large level area for a lawn and 2 more large raised areas at the top by the fence.

I now have 2 very large piles of topsoil and clay,

I will use allot of the clay filling up the bottoms of the beds and raising the lawn areas.

I will have allot of clay left.

My question is can i mix the clay with topsoil to use as my top dressing for the lawn and flower beds?

This will save me buying in topsoil and paying to dispose of any excess clay.

The lawn and beds have drainage.

Any help would be gratefully received.

Thanks Mark.

raisingirl

Depends what you mean by 'clay'. If it's grey or blue clay, it probably has no air in it at all and if you 'mix' it with top soil, it'll just sit in big globs like rather soft stones. It will break down eventually - I mean a few years - with frost action. Some plants will be OK with that - rose family for example. But what you are making is heavy clay soil, so you'd need to understand that with the plant choices. I would go for just top soil for your lawn areas, for example. A mix of top soil, clay, compost and grit might work. The yellow colour clays are sometimes less claggy and break up when they dry out, so are easier to incorporate uniformly.

I would say it's better to try to use what you have, and work with that for the plants, rather than export loads and then import topsoil (which may not be that much lighter anyway, in my experience). If you are patient and don't expect 'fine tilth' anytime soon, you can make a good garden on clay soil.

Last edited: 11 March 2017 14:08:28

Mark Dunn

Thanks for the reply.

My clay soil is light in colour and quite sandy, i live about 500 yds from the sea.

I'm not too worried about plants as i have 4 small kids so I just want grass playing space for now.

The clay and topsoil are already dug up and ready to fill in behind the walls I've built.

I have too much clay and not enough topsoil.

The clay isn't clumping and is easy to dig now it's in a pile.

When all my back filling is done I'll have almost enough topsoil to fill my beds and put a layer down for the lawn but I will need more​.

If i have a mix of say 75% topsoil and 25% clay would it be ok for growing grass and maybes a few veg in the bottom bed.

Thanks again.

Mark.

raisingirl

Reported the advert above.

In response to your question, if the clay is easy to dig then I doubt it'll be a problem in terms of drainage which is the main issue with lawns. You might have to be a diligent lawn keeper, aerating and clearing moss and sanding, etc. I grow lawns on clay and they get very mossy with a lot of clover, but I am not a diligent lawn keeper. 

For veggies, like any clay soil you'll probably get on fine with parsnips and potatoes and find carrots are a dead loss. Brassicas will be OK if you get the pH right (they don't do well in acidic soil), rhubarb and raspberries will thrive. You'll probably need to add plenty of manure and or compost though - the 'clay' I'm assuming is subsoil which will need the fertility building up.

Mark Dunn

I think you've answered my question.

As long as the lawn grows and doesn't end up patchy it will be fine for the kids to run about on.

I'm not an amazing gardener so veg will probably be easy stuff with the kids.

Drainage shouldn't be a problem, im putting a French drain in as i work for a plastic mould manufacturer and got all the pipes and fittings for nothing.

Thanks again for everyone's input.

Best get digging tomorrow.

Mark.