new build house and clay soil

n90bar

Ok, so we are in the process of having a house built by a local builder. The soil is heavy clay. Thinking ahead to the garden which we will do in spring 13 I have been doing some research.

It would seam a good idea to put some sort of soil improver/top soil in before we think about a lawn. Composted bark has been mentioned on the RHS website - does anyone have experience of this?

I am planning on buying some screened topsoil aswell but just wondered if the composted bark would be just as good aslong as it was well worked into the soil?

Another thing I was planning on was putting in a land drain under the lawn. I know this might seem abit extreme but its not a huge garden and itd better to do it whilst I can.....the garden has been like a swimming pool with our recent wet weather.

Any thoughts much appreciated

Nan_Dingle

the garden has been like a swimming pool with our recent wet weather

You need to think about covering the area in 15cm of sharp sand and laying the turf over that.

chunkychocky

Good luck! We moved into our current house when it was 4 years old. Extraordinarily heavy clay (blue in places it is so solid) and builders rubble. We had to pickaxe our way through the whole garden as it just wasn't feasible to get the spade through it, and it took two of us most of a week to do our small back garden. We collected all the stones (excluding builders rubble) and created a drainage channel from these and it made a huge difference to the drainage on the lawn.

I have no idea about top soil versus composted bark, but from experience I have always regretted it when we have tried to save money and opted for the cheaper option, eg with the turf we just selected a local company who made it clear that it was weed-free etc and when it came some of it had holes in the middle and was very uneven depth across each individual piece never mind comparing one piece with another.

caeler

I've been in my new build 2 years and have been struggling with the soil! I ended up removing quite a bit and adding compost and top soil and it is slowly starting to make a difference. On the plus side I've dug up some really impressive stones for my rockery! :-)

Yorkie1

It has been a very wet year, but if the garden area was almost permanently soggy then I'd consider putting in land drains at the start.

Composted bark will help to improve the soil structure a little bit; manure is the generally advised best organic matter. The difficulty is that if you try to add top soil on top of your existing clay, you may end up with a 'pan' of clay where water does not drain away.

Sort the drainage out, add organic matter, and if need be incorporate top soil by digging it in. Or add some horticultural grit.

wellused

My front garden used to be very heavy clay when it dried out in the summer you would need a pick to break it, I dug soil improver into it on a couple of occasions and didn't notice any improvement, after doing some building work I ended up with the best part of a ton of sharp sand left over which I again dug into the front garden. I then came upon some free bark chippings which the council had in massive heaps, when it was bagged up you could feel the heat in it, this I used on the front garden as mulch but after 12 months it had rotted down into the ground, I reapplied this lovely free bark chippings for another 2 years when my supply then dried up. The result is a front garden that is well drained with soil that crumbles to the touch, I swear that the sharp sand and composted bark did the trick.

Davesnave

Composted bark is quite hard to get hold of in some areas, especially buying it by the tonne, but ordinary bark/shreddings will rob the soil of nitrogen while it decomposes, so bear this in mind if you are tempted to buy those instead.

Bark will certainly help add organic matter, and I agree with the poster who suggested very sharp sand. Again, it depends on your area, but where I am, Cornish grit would be a natural choice to buy in tonne dumpy bags.

French drains are relatively easy to put in if there's nothing in the way, so I don't think it's OTT to build one under the proposed lawn area while you have the chance. A bit of preparation will pay dividends later on.

If you buy a load of top soil, do check it on the lorry before they tip it! An acquaintance took it for granted that he would get lovely top soil when he ordered some, but what arrived was awful. As the lorry was long gone by the time I told him it was rubbish, he decided not to make a fuss. About half of the planting we did there was dead inside a year.

n90bar

Thank you for all the advise. I was definitely considering a land drain my issue is the soak away really.....any ideas?

cyclonebri1

In think your ideas are sound.

Given a blank canvas, by far the easiest way to approach this would be to import soil as you yourself suggested. Forget trying to add soil improver's or compost etc, for the amount you would need it's costly.

I don't just mean a sprinkling over the top either, I would get the builder to remove a good layer of the clay soil, possibly a foot or so.

I would then trench out in a leaf vein pattern and install perforated weeping pipe in a bed of pea gravel. New soil over the top. Then it's time to add compost.

All this assumes you have somewhere to drain the run off to??

sussexbaker

Hiya

I'm very interested in this thread as I've got something similar. Quite a large garden which is heavy clay. I've been toying with the idea of putting in a land drain(s) but I have a problem that the natural place to run off to is to the north of the garden, whilst the slope of the garden runs west to east. I assume I really want the drains to follow the slope of the garden? (I might actually have to think about terracing or something).

Nan_Dingle

The garden in the house I've recently bought is also a clay horror. Not helped by the previous occupant "returfing" from a local field (so it appears) and also in an area of heavy rainfall.

TBH, I think the issue is there's minimal movement of water through the clay, so I'm not sure land drains would help that much, plus they get blocked up.