I feel your pain! I am potting almost 100 cuttings this coming week, and the soil (Al's Gritty Mix, from the Container Forum here) is costing me about $120.00 total, but the 3 gallon containers were $31.00 for 100. Mine are not to be for sale. They will be for us here, but the scary thing is, In two years, bigger pots and more potting soil, and two years later, move up again, and again...

I just did the math, and if I sold these things, considering the labor, and the expense put out for soil, fertilizers, pest control, containers, plant stakes, etc., I know what I would need to charge for them, and nobody would pay that!

There are dozens of soil mix recipes here:

Here is a link that might be useful: Soil Recipes

The cost of the soil is more than the cost of the plants.

If you have room in your yard, call a landscaping supply company and order a full truck load of the bark. It's amazingly cheaper that way than buying by the bag. They will deliver it with a dump truck.

If you've got a pickup, you can go down to their yard and buy the bark by the square yard.

You can get large bales of pine shavings at the feed store, sold for horse bedding. That needs to be aged before you use it. Also, they carry granite grit in 50 pound bags. They sell it for chickens.

I bought a 10 yard dump truck full of coarse sand. Think you'd never use that much? I've used almost all of mine and I'm not growing any plants for sale.

It's probably possible to buy a dump truck load of granite grit or pumice.

See if there is a green house supply company near you. They have perlite in giant sacks. Much cheaper than buying it in the little bags at walmart.

I do have plenty of room for whatever. I may get a truck load of sand and bark. I am sure I will us it quickly. Thanks.

Most commercial nurseries do not mix their own potting soil. Your landscape supply should be selling to them and some will also sell to you. I buy #1 nursery mix for about $45 a cubic yard. Every landscape supply in this area sells the same thing for about the same price. Some will only sell in 20 yard loads others will sell as little as you want to buy. Al

Thanks Al, I may try this, but I am not sure there is a source close to me. FWIW my dad owned a retail landscape nursery, but he is no longer here so I can't ask him what he mixed. I helped him for years, but I was just a child then. Wish I could ask him now...

I don't know where you live but here in northern California there are many wholesale nurseries who produce for all the retailers. Ask any of them where they buy their potting mixes. Our closest supply makes and sells 10 different nursery mixes. Al

There are several places around here that sell bark. I'm checking around to see who has fines and what the price is.

A local tree service chips whatever they take out at the site. Those are large chips, and no good for potting. But then they go back to their yard and run the chips through a grinder.

They have a fine ground wood mix, not as fine as sawdust, with a very nice texture for $15 a square yard. I'm going to buy a couple of yards of it. It's very dry and well aged, but because I have no idea what plants went into it, I intend to compost it before I use it.

Mostly the tree services prune and remove unwanted trees. We don't have any rampant tree diseases in my area, except for pine bark beetles. But still, a couple of weeks being heated in a compost pile won't hurt.

I started too late in the day and the other bark yards were closed when I got there. There was a $32 sign on one stack of stuff that I could see, but don't know what the product was. Large bark for ground cover can be pretty expensive, and no good for potting. So I will stop by and see what else they might have.

There are a couple of local guys who will deliver a truck load of pine shavings for use as horse bedding. Those would be useful if you are growing acid loving plants.

A local bark yard has fir bark fines for $26 a cubic yard. They appear to be aged and look perfect for potting soil.

Their minimum delivery is 5 yards, and to my house it is $40 delivery charge (I'm about 15 miles away). I intend to go in with the pickup truck and buy just one yard.

They also sell potting mix, sand and rocks, all sorts of bark, mushroom compost, and big piles of stuff that look interested, but that I didn't ask about.