PEAT BASE MIXES (photo)
Peat base mixes are very light and hold a lot of water. The mix typically has some perlite and humus mixed with peat moss. Straight peat moss is too fine to use for orchids. When buying this medium, just ask for a "peat base potting mix." CAUTION! Peat base mixes can stay moist and cause root rot. If you over water or you have problems with your pots not drying out, do not use this type of medium. If you live in a very dry area or do not water heavily then this would be a good medium to try. I would use it on the terrestrial orchids and those that like to be kept moist such as Paphiopedilums and Phalaenopsis. This mix should not be used with tree fern, cork or osmunda. It can, however, be used with bark. Peat moss decomposes quite rapidly so you will need to repot more frequently when using these mixes.
COCONUT FIBER AND HUSK CHIPS (photo) These mediums are starting to pick up in popularity. They hold moisture up to seven times its weight and will last for years. They are also very porous and easy to handle. The coconut fiber is excellent for lining baskets and for use with orchids that like to be kept moist such as Paphiopedilums. The husk chips are 1/4" to 1/2" in size and works very well in pots. It has been used for years in Holland for Cymbidiums and Phalaenopsis. The price for these mediums is very reasonable at this time. You can purchase it for around $1.00 a pound.
ROCK WOOL (photo)
Rock wool is a medium produced by spinning volcanic basalt rock in blast furnaces. It has been used for years as an insulation in homes and buildings. Oil that is in the insulation type material is removed when the product is used for horticulture. It can be mixed with bark or used alone. This product lasts virtually forever and has very few problems with insects because it does not break down and decay when used alone. It can be purchased in cubes, mats and pellets. This product tends to pack tight so many growers will mix Perlite or tree fern fiber with it to maintain an airy consistancy.
