Potting Soil Recipe... your opinion please

From Better Homes & Gardens
New Complete Guide To Gardening Copyright 1997

A Simple Soil Mix Recipe

1 part good loamy garden soil or commercial topsoil
1 part organic matter (peat moss, leaf mold, compost)
1 part sand, perlite or vermiculite
¼ part bonemeal or rock phosphate (for phosphorus)
¼ part greensand, granite dust or langbeinite (for potassium)

Container gardeners often develop their own secret recipes for the growing medium for their pots. If you’re an inexperienced container gardener, try this recipe

The soil in the mix holds nutrients and water and buffers changes in pH and nutrients. The organic matter improves texture and hold water and nutrients. The sand, perlite or vermiculite encourages good drainage: however, sand is heavy and may make moving large containers difficult.

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Notes From Judy:

Greensand is suppose to be great for clay soil – search the Internet for more information.

1 part sand, IMO, is way too heavy, especially since most commercial Topsoils now contain sand. I would cut at least by half and possibly make that ½ part be vermiculite since quality perlite is hard to find. Most of what you can buy in a “big box store” floats to the top when you water the plants.

Slow Release Fertilizer- I would add at least a cup of slow release fertilizer to the mixture

Hint: I mix mine in a concrete mixer
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Experienced Container Gardeners, what is your opinion of this recipe?

Judy

Judy, when I make my own potting medium, this is what I used

2 parts peat moss
1 part mason sand
1 part compost

I mixed mine up on the cement shop floor with a scoop shovel. (was my aerobic workout if I mixed up very much....LOL) My "parts" were 5 gallon pailsful, so with 4 pails full in a heap, that was quite a bit of shoveling. :>)

I use aquarium sand. It's expensive, but it never, never cakes. I also have to add in a little earwig and sowbug bait because my containers are usually redwood and attract too many of those horrible things.

I use sterile playbox sand from Home Depot.

My recipe:

1 part peat moss
1 part top soil
1/2 part sterile playbox sand
1/2 part composted manure

~* Robin

Judy - Did you use your recipe? Looking at it gives me the impression that drainage & aeration would be an ongoing problem with this soil. The mix seems to be comprised of nearly all small particulates, which almost insures compaction.

Though builders sand or play sand favor drainage in containers, the small size of particles robs valuable aeration. An excellent substitute for sand (if it's needed) is starter grit. This is crushed & screened granite which is highly irregular in shape. It promotes drainage & aeration in container soils, but holds little water. Most container soils can do perfectly w/o any sand, using perlite as an aid to drainage/aeration instead.

Al

This message was edited Jul 8, 2005 12:20 AM

Al, where does one find starter grit? And another question for you: I've always used ProMix for my containers. Where does that rank on your list of acceptable container soils?

Thanks,
Barbara

Al,

I just mixed up my own soil cause I couldn't find one to suit me. http://davesgarden.com/forums/t/502627/

Once I wrote it down, it looked heavy on fertilizers but the Brugs have done very well in it.

In our area it get really hot in the summer so I wanted a soil that would hold the moisture, otherwise I would kill myself trying to keep everything watered. My recipe worked well for me.

Judy