ABSTRACT
Many other methods of soilless culture are being used successfully. Some of the media used are peat, vermiculite, perlite, pumice, rice hulls, and plastic Styrofoam. Perlite is a siliceous material of volcanic origin, mined from lava flows. The peat-lite mixes are made from equal parts of sphagnum peat moss and either horticultural perlite or No. 2 vermiculite. Herbs may be grown in a number of soilless substrates such as sand, peat-lite mixes, rice hulls, coco coir, perlite, foam, rockwool, and nutrient film technique (NFT). Perlite blocks are becoming a competitive alternative to rockwool blocks. They are gaining popularity in the propagation of young tomatoes, peppers, cucumbers, and eggplants. Perlite culture is an alternative to rockwool culture. In Great Britain, it is considered the third most important hydroponic system behind rockwool and NFT. A more recent development in column culture is the use of Styrofoam pots stacked vertically. Sack culture is a simplification of column culture.
