[Swing Swang]

I've got very heavy clay soil to which I keep adding a lot of well rotted stable manure/straw on an annual basis.
Soil depth is a problem. I'm on top of a hard chalk pan which is varies from one to two spits below the surface.
I'm in the process of building paths, and in so doing have the opportunity of digging out the soil to increase the depth of the cultivated land.
Because I could change my mind in years to come I'm seating the paving slabs on sharp sand rather than a mixture of scalpings and sand (which can be dug over in the future if required), also I'm hoping that this will improve drainage too. The sand is up to 20 inches deep in a very few places, but is usually 4 inches deep as I've designed the paths to go over places where the soil is the shallowest (cleaver hey!)
Because I'm ordering a lot of sand I could dig some (4 inches say) into my heaviest beds to lighten them, however I've now done my winter digging so don't really want to dig again, and in anycase the sand won't be delivered until March.

So the question is, if I put a 4 inch mulch of sharp sand around my plants, then dig it in next winter, am I likely to have any problems? Sharp sand is quite reflective so will this scorch things, and is 4 inches too thick a layer for the underlying soil to cope with?

I'd probably be quite selective on the crops that I'd treat like this, and am inclined to do this around a large bed of sweetcorn, white maize (mielies), and a variety of winter squash and courgettes.

Your comments appreciated,

Thanks,

SS   

[Trillium]

In theory sand mulch should work, but reality might prove different. One thing I remember about summer at the beach was usually getting my feet burned by the scorching hot sand. I wonder if the heat would be too much for your plants? 4" is a fair bit to add as a mulch and would tend to shift against plant stalks if you walk near the plants. Eventually plant leaves might shade the sand but it depends what you're growing and how close the plants/seeds are together.
I too have soil such as yours but mine is one spit deep before it hits 'the junk'. I find that mulching with straw or shredded leaves works much better, causes no problems (if you have slugs the mulches aren't what attracted them anyway), and really adds to the hummus rather than simply lightening the soil. I'd add some sharp sand if I could get it, and would simply rotovate it in (borrow or hire one for the job if you haven't one) which would do a much better job. But I'd still be adding the same amount of shredded leaves, manure and straw. Definitely get a big compost pile going too.
And, cats might find your sand mulch VERY attractive as giant litter boxes.

[Coltar223]

Swing Swang, I agree with Trillium. Here in Virginia I have a heavy clay base, I have spent four years ammending my beds and incorporated sand as part of that. i am now pretty happy with the results. I did use washed sand and gravel finnings.

I would be concerned with the salts present in the sand, especially as there would be a concentration around the individual plants. Could I suggest you take a soil sample and do the water test in an old jam jar. That will give you a visual to see the make up of your current soil type and maybe an idea of what to amend with.

Do you have a stone quarry near you? If so, you might enquire with them to see what they have as finnings ( by product) of the gravel processing. These finnings contain many valuable essentials as well as being excellent ammeliorants.

[Swing Swang]

The whole issue of salts (and cats) was not something that I'd thought about.

Thanks,

SS

[Swing Swang]

Thought that I'd post some feedback. I did use a good 4 inch mulch around my peas and broad beans in spite of some of the feedback above. They thrived, so no apparent problems with salts leaching into the soil. No weeds or slug damage at all, and now that I've forked the roots and sand mulch into the topsoil the top 8 inches of soil is now free-draining and loamy. If I ever have any more building work to do again I'll certainly over-order the sharp sand again.

SS

[Swing Swang]

PS I also dug lots of organic/rotted manure into the ground before the sand mulch was applied.

[SG6]

I used sharp/coarse sand as a mulch this year on my onions also for the reason to be able to dig it in afterwards.

Worked well. Only put down 1 to 1.5 inches but being light in colour it reflected the light and water/rain went through it easily. Onions came through it easily and very few weeds made it through. Soil underneath didn't lose water and dry out as hoped.

Just lifted half the onions and dug the half patch over.

Oddly I recall when they rediscovered the lost gardens of Heligon many years back they renovated the beds and replanted, the soild then promptly reverted to "poor" soil again. The reason was they had not added grit/course sand. They had to redo parts all again this time adding grit. The reason was that the grit/sand stabalised the changes made to the soil. So I would say that if you are trying to alter the composition of your soil it will need the sand/grit to maintain the change.

Never heard of it again but the information stuck.