Perlite is inert, Cheryl. All it does is "open" the soil, allowing more aeration and of course better drainage. Though I still use an awful lot of super coarse perlite, since I make my own potting soils (8 cu. ft. of perlite each year), I have also begun to use cypress mulch in my potting soils and in my orchid media. I buy the cypress mulch at Lowe's and it is a "clean type", with nothing added as far as I can tell. I get it in 2 cu. ft. bags and go through 6-8 bags a year. I also use cypress as my landscape mulch, but it is nothing like that I purchase bagged.
