Joseph H. Mellichamp proved the carnivorous nature of this genus. This finding was supported by a study by J.S. Hepburn, E.Q. St. John and F.M. Jones in 1920. Extended field surveys and laboratory studies by Edgar Wherry in the 1930s greatly increased the knowledge of this genus, which has further been extended by the more recent works of C. Ritchie Bell (1949–52), Donald E. Schnell (1970–2002), Frederick W. Case (1970–2000s), and T. Lawrence Mellichamp (1980s-2000s). CultivationSarracenia are considered easy to grow and are widely propagated and cultivated by gardeners and carnivorous plant enthusiasts. Several hybrids between the very hardy S. purpurea and showy species like S. leucophylla are becoming common in garden centers in North America and Europe.Sarracenia require constantly moist-wet, nutrient free acidic soil. This is most often achieved with a potting mix consisting of peat moss mixed with sand or perlite. As their roots are sensitive to nutrients and minerals, only pure water, such as distilled, rain, or reverse osmosis water, can be used to water them. Sarracenia prefer sunny conditions during their growing season but require a dormancy period, with decreased light and temperatures, of a few months in the winter. PropagationSarracenia do not self-pollinate and therefore require hand pollination or access to natural pollinators such as bees. Sarracenia pollen remains potent for several weeks when refrigerated, and so is stored by cultivators and used to pollinate later-flowering species. Given that all Sarracenia hybrids are fertile and will hybridize further, this characteristic allows cultivators to produce a limitless number of variants through hybridization. The copious seeds store well if kept dry. In climates or seasons that cannot provide the cold, damp period of stratification required by the seeds for germination, growers mimic this condition by placing the seeds in a refrigerator for 2–6 weeks, depending on species. The seeds are sown on the surface of their substrate and germinate when transferred to warmer, bright conditions. Sarracenia seedlings all look alike for the first two or three years; the plants reach maturity after four or five years. Regular fertilization (twice a month between April and September) with a balanced fertilizer at the rate of 1 teaspoon per gallon (using a 15-16-17 peat-lite or similar fertilizer) will speed their growth and time to maturity. It is advisable to leach regularly with pure water to prevent the buildup of solutes (fertilizer salts) in the soil. Deep water in a potted