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Potting soil formula? Perlite substitute? Answered

I want to formula my own potting soil - 50% soil, 50% compost, but how much perlite? And possibly substitute something else for the perlite - more "green", more natural, cheap as "dirt", just as available?


i put the same amount of everything. now i have never killed a plant, but again i have never used rooting horomone. My mix looks like concentrated miracle grow potting soil. Cut hyacinth, goldflame and clematis for this.

I have used a equal amount of everything. Looks like concentrated common potting soil. I'll see what will happen. With my luck, nothing c:

perlite and vermiculite are considered non-renewable resources. Check out

http://homeguides.sfgate.com/alternatives-vermiculite-perlite-43502.html. They suggest ground pine bark or ground cocanut shells as a replacement for vermiculite. To replace perlite they suggest styrofoam, parboiled rice hulls or sand.

hey guys...I just wanted to ask about substitutes...we don't have pumice or pelite in our country...can anyone please tell me the next best thing ?

I don't know if I can do any better than Gorfram (great answer, BTW) but I'll throw in my two cents. The soil mixture I use is fairly simple, and probably very similar to what you've seen else where:

3 parts compost
2 parts perlite or vermiculite (to address your concern I'd agree that pumice is a good way to go)
1 part crushed eggshells (this can be difficult in large boxes, but for smaller containers it's easy)
1/2 part dried manure
3 parts peat moss

The soil is loose, nutritionally rich, and holds water very well while still draining well (does that make sense?).

How have your results turned out?

pearlite substitute - vermiculite? Gorfram has it down :D

I use pumice (available at most/many garden stores) instead of perlite. It's slightly more expensive and a few garden stores don't carry it, but it's environmentally sound, you don't have to worry about inhaling pumice dust like you do perlite dust, and it doesn't crumble or break down over time. It also doesn't look and behave like some sort of mineral-based styrofoam floating around in my plant pots, which is the thing about perlite that annoys me the most. :(

I'm a balcony gardener, so the mix I actually use is low on soil (which I have to go out & procure), and on weight (so that gravity doesn't someday suddenly make me into a patio gardener :). I'll give you both my own potting mix and the mix I'd use if I had access to large amounts of soil and of weight-bearing-capacity.

Low-weight, low-soil-content Balcony Mix:
  • 4 parts finished, sifted compost
  • 4 parts pumice
  • 1 part soil (e.g. dirt, ground, earth...)
  • 1 part sand (I just use builder's sand)

"Normal" Mix:
  • 3 parts compost
  • 3 parts pumice
  • 3 parts soil
  • 1 part sand

And, while I'm at it...
Well-Drained Sandy Mix (for Mediterranian herbs & the like..)
  • 2-3 parts finished compost
  • 4 parts pumice
  • 1 part soil
  • 2-3 parts sand

I don't like to wear gloves for mixing the soil, and (while it doesn't do my fingernails any good at all) the pumice smoothes any callouses or rough skin right off my hands as I mix. :)