Chicken scratch is normally edible, whole grains to give them something to pick at, not necessarily as their main feed.

A grit intended for chickens can be suitable for mixing with your soil but it may be too fine and it may contain limestone. For a large outdoor bed you should be looking for a quarter inch or half inch grade, a mix of grits is OK. Any limestone or shells in their aren't the end of the world but may cause some plants to be unhappy.

You don't need to wash chicken grit or any other grit unless you have reason to think it includes salt. Taste it, you know what salt tastes like. For a pot you might want to wash or sieve away any fines but it won't matter in your bed. Simply mix it with a reasonable non-clay loam. If your own garden soil is heavy clay then buy in some topsoil. Play with your soil in a big pot and see that water runs through quickly and that it doesn't become soggy. Add more grit, the plants will spread their roots in a big bed to find even tiny amounts of water.

Last thing, remove the bottom from your container and stand on a surface where water can drain away. Or at the very least put holes in at and then raise it so that water can drain away from the holes quickly.

Thanks shrubs n bulbs. The girl at the store counter seemed puzzled by my request for chicken grit so said she thought I must mean chicken scratch. I didn't know better. So it sounds like the grit is not available after all. They only had feed and scratch.

As it happens I do have pretty bad heavy soil with clay so will have to buy some soil in bags and add that to whatever small gravel I can find for this project.

Unfortunately, I don't think I have seen any store soil yet that is not primarily a peat moss mix. I am hoping some Southern Californian will know of a locally available product that is better.

As far as drainage- I had already planned on that. Also our rainfall average is only slightly more than desert.

You might try paver base as a lower cost substitute. Chicken grit here sells for about $6.00 per 50 lbs. Paver base for about $2.50 for 50 lb bag at our local home improvement stores. And it works just as well.

Dave
Milwaukee

Several grades of turkey grit should be available as well. In my location, it's granite.

Al

Ours is granite, too. (Avoid oyster shell grit, which'd be primarily for calcium for layer hens.) It's odd that you'd have a local store that would supply scratch grains but not grit!
I've used a fair amount of the stuff this summer. I can't find a non-peat-based C&S mix around here, either, so I wind up making a mix of about 1:1:1 with mix, grit, and perlite (pumice is better than perlite, but not available here unless one's willing to pay exorbitant shipping costs.)
I assume the paver base Dave mentioned is the same thing I know as builders' sand. It's a coarse sand, or more like a fine gravel, mix, and makes a darned good ammendment. I didn't realize it was that cheap. (When I mix my own concrete it's always small amounts, and I by already sand-mixed Ready-crete.) Cheaper sounds good to me!