The best source for info on container mix recipes is the Container Gardening forum here as that is their focus - as opposed to folks who do in-ground gardening. That said, there are literally hundreds of discussions all over the forums here on 'best container mix', 'best potting mix', 'make your own recipes' for container mixes, etc. that the search will pull up for you. Many of them address specific plant's needs as no one mix works for all. Many cover the pH issues, water retention/drainage issues, compaction issues, nutrient supply/retention issues, mix sustainability issues (use and reuse), etc. so lots of good information is already available. Common points reconfirmed by all the discussions is that (1) container gardening is unique, a different world that shares little in common with in-ground gardening, 2) that the use of "dirt"/garden soil in a container is not recommended for several reasons, that (3) there is a big difference between "potting mixes" and "potting soils", and that (4) there are many high quality bagged potting mixes available depending on local availability. Probably the one container mix that gets the most discussion on the various forums is the 5-1-1- mix recipe discussed in great detail over on the Container gardening forum. Dave Here is a link that might be useful: Container Gardening forum

Do you have an easy recipe of making your own mix for a gardening-beginner? Yes. I would recommend using what is known around here as 'Al's 5-1-1 mix' for annuals and perennials grown for just a year or two before being repotted. For plants that will stay in the same container/mix for more than 2 years I would recommend what is known around here as 'Al's Gritty mix'. The 5:1:1 mix is 5 parts pine bark (very small pieces), 1 part perlite and 1 part peat. The gritty mix is 1 part pine bark fines, 1 part Turface MVP and 1 part grower grit (#2 sized). For more information on this I will refer you to this thread. Don't get too hung up on specific ingredients and percentages. The principle is using ingredients that will be of a large enough size (above 1/16th inch) for as long as the plant will be in the mix. This provides superior aeration. The higher the percentage of organic matter such as peat or bark, the faster the mix breaks down and aeration suffers. The bark breaks down much slower than peat though. Anyway, read the thread and you will learn a lot. If you can't find suitable ingredients to make your own mix in time to get the season started then just get the regular MG potting mix and take until next year to learn more and locate sources for ingredients you want.

Last year and this I kept track of how many containers I filled from a $30 compressed bale of professional growers mix. Last year it was 200 gallon-size milk jugs from a 3.8 cu. ft. bale which came out to 15 cents per container. I'm guessing it would take a whole lotta potting mix to match that altho' I haven't done a side-by-side comparison. Like quilt_mommy I don't have space inside to start plants other than a small tray table in front of my south-facing bedroom window. I can't be bothered with that since WS is so much better all around for growing everything, including trees and shrubs. I still have the 4-5 unopened bags of seed starting mix I bought 3 years ago before stumbling onto the winter sowing method. That said, I realize not everyone has a nursery supply business close by as I do where I can buy the compressed bales, have them loaded into my car and set them inside my garage until they're needed. I've got 1/4 left of bale #3 this year + a dandy array of WS containers lining both sides of my breezeway.

The thing about potting soil is it's not soil. It's usually peat moss based, with some vermiculite &/or perlite mixed in to keep it from caking, and a bit of fertilizer. You can buy all these things separately but it doesn't save any money. Some potting soils contain municipal compost, which you can also make yourself. For me the most economical way for potting lots of plants is to buy a big cube/bale of Pro Mix. It's good for seedlings and adult plants alike, and is better quality than most bagged soils.