re; Perlite substitute
BBCNURSERY@aol.com (Wed, 05 Jul 2006 23:31:22 PDT)

If your local rock dealer has a fairly inert rock source and if you don't
mind the added potting soil weight I find that 1/4 minus gravel gives excellent
results. It is cheap and if the fines bother you just run the gravel
through a hardware cloth sieve. Here in the rainy Portland Area I find that a
great mix for bulbs in pots is equal parts soil, the above gravel and coarse peat.

Greig Warner
Vancouver, WA