Hi Peter,
This has been talked about time and time again here. Your best bet would be to do a search on soil or "pre-mixed soil". Everyone will tell you something different. And to tell you the truth, I really don't think there are any "good" pre-mixed soils. They are just not fast draining enough. If you don't want to mix your own soil, there are a few sellers on Ebay who sell soil that they made, and it's GREAT. Very very fast draining and "gritty" (it has lots of perlite, pumice, sand). You can also do a search for "cactus soil" on Ebay...there are other soil mixes that have haydite. You'll be paying a lot more money than if you bought a bag at HD, but if you don't have many plants it's worth it.
Hope that helps,
Gabi

Here is a link that might be useful: cactus soil

Hi Peter,
One more suggestion. You can always go to HD and buy a bag of any C+S mix, and then a bag of perlite (will cost you about 3-4 dollars for each one), and then mix them at home. That way you can just bring a big garbage bag to work the next day and repot your succulents. I would mix about 2 parts soil to 1 part perlite. To make it easier, you can just dump the bag of soil in a garbage bag or large bucket and then dump half the bag of perlite in (maybe even more than half) and mix them. Easy, right?
Gabi

That idea, of mixing standard cactus soil you buy with perlite, is exaclty what I do, with considerable success. The only down side is that most purchased soils have peat moss, and I do think it encourages mealy bug. My new goal is to create compost and mix that with perlite.

Hilary

If you want peatless, go with coir. I bought blocks of Bed a Beast at Petsmart. When you add the water, it makes 7 quarts. Peter, I think if you can get your hands on Landscapers Mix or Pine bark fines, I would go with that mixed with perlite or small pea pebbles or both. I personally am not a fan of perlite because it floats. I also like the weight added by the pebbles because all, well, most of mine are outside. If you do a search of soils, you'll find a longer thread of what I mix, but it's a lot of work.

Gabi you are absolutely right. The pre-mixed soil, is the one you mix yourself for your own growing conditions. My friends mix their soil in the childs low step in plastic swimming pool, and use a hoe to mix it with. Good luck, Norma

I recently read in a book on succulents and cacti that sand should not be used because it "clogs the mix" This is contrary to everything else I have ever read or heard, but that is what was said. I always thought sand provided drainage...has anyone heard anything similar to this quote about sand, and should I continue using it?

Eileen

Adding sand to a potting soil mix is not usually a good idea. Sand is not coarse enough to improve drainage with typical potting soil ingredients such as peat, bark, or coir, it will just weigh down the soil and clog up the spaces which already exist. In these soils you need a very coarse, and preferably light, aggregate such as pumice or perlite. Grit is sufficiently coarse but can collapse "fluffy" soils such as peat.

Sand can improve the drainage of loams, that is soils which are based on clay. In circumstances when high levels of clay particles cause a drainage problem, the drainage can be improved by adding enough sand that the clay particles are kept apart and air pockets are maintained. Cacti and succulents are often grown in loam soils, but in a pot even a sandy loam generally has insufficient drainage and a more coarse material such as grit is also required.

In summary, sand will rarely help drainage in a pot, use a material with larger particles like pumice, grit, perlite, etc.

Excellent explanation, Ian. I concur completely. NO sand!

Thank you very much for your excellent and thorough explanation, shrubs. I have been using sand as an ingredient not only for my succulents, but for other plants as well; no longer! I will be using grit for succulents and perlite for other plants, and once again, a big thank you! I have only been taking a serious interest in plants for the past year and have a lot to learn - gardenweb is the best resource I have.

EIleen

I've often wondered why so many use sand. If you think about it, it stays wet a very long time too. I remember a friend of mine had a sandbox when we were growing up. It was just some 6 by 1's nailed together to make a box set right on the ground. If it would rain, it would take days for the sand to completely dry out. I think there are different sizes of sand. I read somewhere that anything 3mm or 4mm and under is technically sand. To me 4mm is grit not sand, but I think that is splitting hairs. Whatever you use, it is best to use something that is jagged or square in general shape. The rounder the particle the easier it is for the finer particles in your organic portion to settle around them and clog the soil.

I'm one of 'those' who use sand..Play sand is NOT the type I use though..it's too fine and will hold water.
I got to Home Depot, buy Builder's sand which contains sand and gritty pieces.
Mix my own soil using sand, perlite, and all purpose. Been using it for yrs w/o problems and is quite well=draining..but that's just me..
What works for one may not work for antoher..Toni

For my mix I use:
2 parts Schultz aquatic plant soil
1 parts Schultz perlite
1 and ½ parts whatever organic matter I have on hand. But don't use any kind of peat.

My succulents seem to enjoy it.