[brianc]

Hi all.
       I have heavy clay soil i have been told to add sand to it would it be builders sharp sand or something   
       else. And how much.
                                   Thankyou.
                                   
       

[Kleftiwallah]

Better still - Oss muck!  As much as you can find.  Farmyard manure - sheep muck, all you can find.  Clay soil is not the bogeyman of soils, it can be improved and its water retentive qualities can be a godsend.

Don't dispare,  I would always prefer clay soils to sandy any day.

Cheers,  Tony.

[Christine]

Hi Brian  join the club. It'll take a few years to improve things but it can be done. Kleftiwallah is right - add as much farmyard and horse manure as you can find. You want it older and mature mind you. It's a regular autumn and spring job digging in manure.

Also you want to invest in the biggest composting facility that you can provide for yourself so that you have mulch available and also stuff to dig in at the end of the season. The RHS is good on composting and gives lots of tips. Get to know your friendly neighbours who may have grass cuttings and soft hedge trimmings (privet good, ivy is a no go). Scavenge around for who can provide you with plain brown cardboard (other sorts just don't rot down).

Plant a cover crop over the winter that you can dig in early spring before planting.

It's taken me seven years to get my clay down into a workable soil but it's always been very productive for crops.

[Hampshire Hog]

Only point I would add to existing comments is that you can also add spent mushroom compost which you may be able to get cheaply if you have a mushroom growing farm nearby.

Cheers HH

[mumofstig]

If you use mushroom compost, don't plant potatoes in it, as it can make them scabby 
http://www.ledburyallotmentassociation.co.uk/live/news/news17.asp

[ARPoet]

As Above, also, In the autumn collect loads and loads of leaves and add them to your muck/compost heaps.... Shredded paper too can be added to heaps, also spent hops.
I have a rolling program of soil improvment for my heavy clay. I have a free supply of hos muck with 3 heaps always on the go. I dont dig it in, but scatter it on the bare soil in autumn and let the worms do the work.

[Auntiemogs]

Yes, sharp (builders) sand and as much rotted manure and compost as you can.   

[brianc]

Thanks for the replies i will keep the manure going in and add some sharp sand as well.
Would fresh horse manure be alright to spread in the autumn? as it would have several months to degrade?.

[colin120]

I used sand and (rotted horse manure from the allotment) in my garden as it was very clayey  didn't work for meeee. planted some cauliflower seedling and cabbages seedlings into this new sandy bed within weeks they just died off.

Removed as much of the sand and horse mix then went and brought some top soil then added new horse manure now going to try again and see what happens.

[LotuSeed]

Thanks for the replies i will keep the manure going in and add some sharp sand as well.
Would fresh horse manure be alright to spread in the autumn? as it would have several months to degrade?.

Fresh horse manure in the autumn is fine. By the time winter is over it will have rotted down.

[fatcat1955]

Gypsum is the best clay breaker.

[LotuSeed]

I used sand and (rotted horse manure from the allotment) in my garden as it was very clayey  didn't work for meeee. planted some cauliflower seedling and cabbages seedlings into this new sandy bed within weeks they just died off.

Removed as much of the sand and horse mix then went and brought some top soil then added new horse manure now going to try again and see what happens.

I've used a combination of sand, horse manure, compost AND topsoil. Maybe you just needed more soil added to the mixture? Purely conjecture on my part. Forgot to mention there was a fair amount of double digging and mixing everything together.
Last Fall I raked the leaves into a pile and the ran over it with a lawn mower. I've been adding that in as well.

[BabbyAnn]

I used sand and (rotted horse manure from the allotment) in my garden as it was very clayey  didn't work for meeee. planted some cauliflower seedling and cabbages seedlings into this new sandy bed within weeks they just died off.

Removed as much of the sand and horse mix then went and brought some top soil then added new horse manure now going to try again and see what happens.

As mentioned, sharp sand is useful in breaking up the soil but it takes time.  Digging it in and breaking up the clay as you do it so that it is well mixed is essential.  It's not a one off exercise either - clay is basically very fine soil so the smaller microscopic particles "slip" between the larger sand granules ... you end up with sand on the top while the clay compacts underneath (anyone with pebbly soil will find that these somehow always end up on the soil surface despite digging and removing them)  As regards your particular problem:

First, cabbage and cauliflower (and other brassicas) actually do better in .... er heavy clay rather than sandy soil.

Secondly, sand has no nutrients so when digging it into soil, you are diluting whatever nutrients are in the soil.  The manure/compost idea will provide some but also consider something like fertilizer to give a boost.  Cabbage and cauliflower need higher nitrogen

Thirdly, sand dries out a lot quicker than clay soil so its possible the roots just weren't getting enough.  Also when planting brassicas, "heel" them in (that is, compress the soil round the roots)

[dave43]

Hi.Brianc
after 10 years of growing on clay my advise would be to add sharp sand to improve drainage, but the most important thing was the addition of large amounts of compost in the shape of oss muck, and three darlek compost bins and a bale of wheat straw every year. if you want sprouts and cabbage to be hard like cannon balls keep your clay but feed it well.

[Goosegirl]

I grow on alluvial silt (similar to clay) with very little topsoil and had to make raised beds. Even so, I needed to add plenty of organic material like well-rotted manure, mushroom compost (actually it is quite cheap to buy), and any compost I could make. What I would say is do not get builder's sand as that is too fine. You need sharp sand with grit, grit on its own or some gritty topsoil. When digging your trenches, wiggle your fork in the bottom and add your material and sand/grit, then backfill with your soil and add your stuff as you go. Don't tread on it - just let it settle naturally. I found that the grit made an almost instant impact but Gypsum is also useful but takes time to make a difference.