I do not live in a warm climate, based on lack of heat in summers, and have acidic soil. I add crushed oystershell or gypsum to my bulb growing areas every few years, and have several species persist as a result, including T. clusiana, T. turkestana, T. sylvestris, T. tarda, and a couple more I can't recall right now. I planted these bulbs in open, sunny spots and do not water in summer so that they can dry down as much as the local climate allows. These species do much better than the hybrids, as deer eat the hybrids with much gusto, and tend to avoid the species. Kathleen Kathleen Sayce PNW Coast, WHZ 8, dryish cool summers & mild wet winters