A wide range of soilless media is currently available to tobacco growers utilizing the float system for transplant production. Most of the media are predominantly made up of peat moss with varying amounts of perlite, vermiculite,and coconut fibers (coir). One of the most difficult problems for growers has been inconsistency in the media from year to year. Because peat is a natural product, some year to year variability is unavoidable. However, many manufacturers of soilless media have procedures in place to ensure that the final product is as consistent as possible.
Pearce, Robert C. and Zeleznik, Jack M., "Evaluation of Soilless Media Used in Tobacco Float Systems" (1999). Agronomy Notes. 19.