What is outside under your feet is soil, all you need do is add organic matter, except peat moss, to that soil to make good soil. Compost, or other forms of organic matter, in quantities large enough to be 5 to 8 percent of the total volume is what you need.
To make a good potting soil all you need is compost.

I couldn't disagree more!! Potting soil or soil suited for growing in containers has very different requirements than soil necessary for inground growing conditions. This is primarily because container culture is a closed environment requiring frequent, often daily, watering, offering a limited root run and with a need for exceptional drainage. Too much organic matter (in the form of any kind of compost) will eventually adversely impact drainage, as it continues to decompose and compact, reducing pore space.

The best container soils generally contain no real soil and very modest amounts of OM. Peat or coir (cocoa fiber) is a good base (yes, they are OM but very slow to decompose) and you do need the addition of pumice or perlite to facilitate drainage and provide porosity. High fired clay (Turface) is a great substitute for these if available in your area. Bark fines will help with moisture retention plus provide necessary texture and pore space. Check out the Container forum for many excellent DIY potting soil recipes, especially any of the posts by Al (tapla).

If you have access to Gardner and Bloome products, look for their Blue Ribbon Potting soil. I've used this product for years and it is an excellent medium for any kind of container growing, especially for long-term containers, which can be a challenge to maintain with quality soil conditions and fast drainage.

Thank you GardenGal and everyone else for their time. I will get this blue ribbon by Gardner & Bloome since I can get that. I have a lot of perennials in pots and I want the soil to last, so my plants last longer than would happen with that blasted Super Soil product that is mostly wood product etc. Glad to have feedback on it.

Gardengal48, DonÂt believe everything you read or hear.


John

Here is a link that might be useful: 100% Compost

These plants are growing in 100% compost and I only water once per week.


John

Here is a link that might be useful: Growing in 100% Compost

Good coir is hard to come by. 98% of the coir purchased in the US is obtained as by-product of the brush and rope making industry in India and Sri Lanka. To make the fibers tough the husks are soaked in salt water. The salts are left in the coir dust that are packed and sold are alternative to peat. In the past there was no market for this waste and it sat in dump and got rained on. This leached the dust and made it a fine growing medium. However nowadays all the old dumps have been used up amd the new dust is not being given time to have the salt leached out before being shipped. So some product come with high ECs an low pHs.
Pls go to my website at www.densuventures.com and click on the research tab.
Let me know it I may be able of further help to you.
Jake

my soil mixture = 33% vermiculite/33% peat moss/33% homemade compost.

As far as coco-coir is concerned, I used it when growing portobellas and would recommend CocoTek as a reputable company that doesn't salt-wash their products.

Of course it's cost prohibitive as it typically costs about $2.00 per brick - which expands to fill about 3.5 gallons.