You're going to get conflicting info on adding sand to clay. In high clay soils adding sand in too high of an amount can lead to making a layer of random soil crusting/bricking. If you put the right amount or less in then it's okay. What's the proper amount...it depends and I don't know.

The safest thing to do is incorporate some organic matter/compost/etc. into your soil...anything but peat moss or similar stuff that holds water. If your clay is heavy clay soil it takes a lot, though.

Clay's good stuff...holds water and nutrients very well...the stuff is hard to work and prepare for planting, though.

Yeah...not all clay is created equal...or drains equally. A Pacific Northwest clay isn't the same as a Midwest pre-Rockies clay or a South-Eastern "red" clay.

...also agree that just topdressing organic matter and/or topsoil onto the soil will eventually do just as good as incorporating. It's actually a better idea if you have the time.

"...also agree that just topdressing organic matter and/or topsoil onto the soil will eventually do just as good as incorporating. It's actually a better idea if you have the time."

It especially works well in a raised bed, which keeps the amendments from washing away.

I always give a lot of credit to worms and ants for the success of topdressing. My soil here in PA is so water-retentive that many things will only survive in a raised bed or on a slight slope...and cultivation of dry or very moist soil is impossible.

There is a better remedy and it is well composted manure.

Composted manure...composted yard waste...top soil...

When added to heavy clay soils all of these do nothing but improve drainage and pore space for oxygen.

This is more about changing soil structure than adding some kind of nutrient value. Clay, itself, is one heck of a nutrient holder for plant's roots to discover along with a pretty nice water retaining quality in the thick of summer. It's good stuff on whole. It's just a bit difficult on roots and pre-planting preparation if the clay concentration is too high.

Oh, and I didn't mean to leave out sand in that last post.

While I'm firmly against using sand in the heavy red clay around my area (and the fact I've built a few small structures using cob clay-sand-straw construction that's stronger than commercial brick) it can work. It's just something I've never felt comfortable with. The suggestion for large grade/course sand in a "test patch" is a great idea, though. If you can create a sand/clay patch that works you can add organic matter (compost/topsoil/etc) in future soil preparations for plantings which will buffer and improve anything you do with the sand.

Sand will do nothing but add pore space for drainage and oxygen access to the roots, but clay is so VERY good at holding water and nutrients. There can be a proper balance between the two and adding organic matter in the future as a top dressing will help it in years to come.

I had a similar problem with blue/gray clay a couple of years ago. In a dry spell you couldn't begin to get a shovel into it and I thought it seemed logical to add sand. I posted the question on the soil forum and was told that if I wanted to make brick that sand would be perfect, if not add compost. I took it a step further and did lasagna layers. I now have some of the richest black soil in that bed. The best stuff of any of my other beds. I planted it with winter squash last year with fantastic results.

I guess I don't understand regarding sand over manure for improving tilth. Doesn't organic matter well in excess of that amount needed for fertilizer alter clay soil structure in a positive way, making it loamy? That has been my experience: pure red georgia clay well tilled with enough poop is crumbly loam. If so, whats the point of sand? Is it that both clay and organic matter will hold water, and sand won't, which helps soil to drain better, and to crust over less? That is one thing I've noticed, no matter how much poop I add, my soil still crusts after a rain. Can sand address that?

If so, I might try a bag of sand in one area. Would a bag of play sand in one area be appropriate?

No, do not use play sand. You will need to use a coarse, sharp sand. These may be called different things in different areas, but look for paver's sand or masonry sand.

I have successfully added sand to my red clay at about a 1 to 1 ratio. I have also been adding a lot of organic matter, but the sand was a big immediate improvement in an area where I needed a raised bed and better drainage.

Steve

I love them all in my clay loam....lots of coarse sand, local peat moss. rotted manure, and compost....all mixed into the topsoil.

I ⥠soil.

Nerdy? Maybe. Still, when i grow up I'm going to marry some well draining clay loam. Hot.

sigh...

Thanks for the help everyone! A road just got paved where I live and there is a pile of sand that I used, but I'm going to get more though(couldn't carry much of that heavy sand) and mix it in real good. I lived here three years and had no success like previous place. Just a bunch of flooding, wet soil, and some white moss looking stuff....

Dealing with red clay soil of TN. Wow, not good for root crops. We tilled the veggie garden, and I added sand and OM. My other gardens have raised beds, where I use a mix of humus, and a little sand. Hope it works!

If you want to understand this subject a little more deeply, check out the link.

Novice 2009, I hope you won't make the mistake of adding a small amount of sand, and then getting discouraged if it doesn't work. As you can see from the link, a loam or sandy loam soil has a big percentage of sand in it. That's why I start out with a one-inch depth of sand, till it in, and then maybe add more if it's needed. That's a lot of sand. For a big area, I recommend a rented tractor with a bucket up front and a tiller in back. Unless you really like pain.

Here is a link that might be useful: soil triangle

If you can spare one season you can try the "green manure" method for clay soil improvement. It works. Last year I let sweet clover grow on my hard clay. Sweet clover can grow about 4ft of root into the clay over the winter. Next year if you don't need to use the soil immediately, you can wait until the clover grows again but before they flower, turn them over.

And you will be surprised how good your soil will be. It really surprised me. I thought clay is forever unusable, but now my soil (the area that I grew sweet clover) doesn't even feel like clay anymore!

I also have clay soil. What I do is mix compost and topsoil into the
clay really good with shovel. If top of soil gets crusty, add compost
on top, don't mix in. That worked very well for me