consider also hugelkultur. I did fight with sandy soil for my first ten years of gardening, and I remember adding chunks of clay to the beds. Years later they were still there, under the sand, unmixed. Hugelkultur provides immediately a safe place for your plants roots. I have planted 5 out of 6 fruit trees with this technique, very pleased.

I have grown plants in Lake Michigan beach sand, that has been amended with ample quantities of organic matter, for over 40 year and although I did try amending with some clay it was too expensive and too difficult, and did not last long enough to be of much benefit. To get enough clay into the soil mix you would need 25 percent or more, a lot.

When getting soil for raised beds you can look around and find soil mixes that meet what criteria you set and that should be a soil mix that is close to 45 percent sand, 45 percent clay, and 10 percent organic matter, and if the proposed supplier either cannot or will not deliver that you go to someone else who will.

Hugelkultur can help get more organic matter into the soil, eventually, but that can take years unless the material put into the soil is quite small.

kimmq is kimmsr

Hugelkutur - I'll look into it. My native "soil" is bad enough, but even well amended with OM in raised beds it dries too quickly. Water is a big worry in central coast CA. I'm about ready to try any means of reducing waste.

It's too much of a gamble to hope that Californians collectively washing their cars will incite enough rain to offset the investment. lol

I prefer granular diatomaceous earth as a water holding additive. It is sold as a soil amendment, oil absorbent or as kitty litter sometimes available at the Dollar Tree.

an affordable sufficiently powdered form of clay doesn't exist, to my knowledge. I also have sandy soils, so I wish it did. Clay is heavy, expensive to move and to dry.

Cat litter certainly isn't powdered, but as soon as it gets wet it makes an incredibly slimy clay paste. I would think over time it would be incorporated into the soil matrix with the action of rain, digging, worms etc. Apparently it works because I've heard more than one account of using it to good effect.

If you were closer I'd be so glad to give you a truckload of brownish yellow Missouri clay!

Turface MVP (or what John Deere Landscapes sells as Turface "All Sport") seems like it might work for you. There's a lot of discussion of this product in the Container Gardening forum. I think it was around $12 or $13 for a 50-lb. bag including tax.

A big part of your problem is the raised bed format. Any soil that is raised up out of the surrounding median grade-level will warm/dry quicker. Even the top of natural hills display this phenomenon. Raised garden beds are notorious for this. With sandy soil, you've got a double-whammy. There really are very few reasons to not use/improve your native soil at your feet.

Adding organic matter is key here. The roots of plants are the best way to inject carbon INTO the soil. Use cover crops whenever possible (I'm a huge fan of white clover, a nitrogen-fixer), and don't rip out the roots if you don't have to. I've had good results with hugelkultur as well. Otherwise continually add mulch to the surface, and let the bugs and worms pull it down.

Also, where drought is a significant pressure, space your plants out 1.5-2 times normal; that extra space goes a long ways toward drought-tolerance for many plants (especially vegetables).

S'all for now, good luck.

I missed that the OP has raised beds. I agree that's not the best approach in a hot/dry climate. There are various reasons people have raised beds, such as accessibility, but if there isn't a really good reason, I wouldn't recommend it in sandy soil either.

I worked yrs trying to fix clay soil. Used a backhoe to break up the hardpan.Then by add LOTS of horse manure and tree clipping I had good soil.Then I moved to where it's sandy.

Only difference is no hard pan. Everything I've read says organic matter and lots of it.

What has to be done is change the structure of the soil.Anything you add is helping.In the fall I add mine and my neighbors leaves.you might look into a cover crop.I like the cover crop as it puts nitrogen back that the leaves take up to brake down

I'm no expert, but. relaying information that I have found.Hope this helps a little

I'm not sure how to email you directly cowchip but I have some ideas that are beyond the scope of this forum that seems to egg on the smartest guy in the room. I should have joined with the screen name KnowItAll and see how that went over but seriously send me your email if you really want to figure this out, it isn't hard and doest involve kitty litter or rotting wood and I'm not selling anything... ;-)

I would be afraid that the clay soil I added would simply wash through the sand (again) and you'd be back where you started. If that were my garden bed, I'd remove the sand and put in some topsoil.

Looks like you can go to my profile and send me an email discreetly and with your email and we can talk it out that way! Thanks!