Growing tips for Darlingtonia californica
Temperature
Up to 30°C in summer, -10 to 15°C in winter. Protect from frost if the plant is in a small pot.
Water
Use only rainwater, demineralized water, or reverse osmosis water. Water that is too hard (high in calcium) will kill the plant within a few weeks. Do not use bottled water, as it generally contains too many salts, which are harmful to the plant. In summer, place the plant in a large saucer filled with water. In winter, keep the potting mix moist.
Fertilizer
Absolutely avoid! This carnivorous plant provides for its own needs in terms of organic nutrients thanks to its traps.
Brightness
Avoid full sun; partial shade is preferable in summer.
Substrate
Carnivorous plant mix is the basic substrate for many species; you can make it yourself by mixing blonde peat, perlite, and vermiculite (4:1:1:1) or blonde peat and non-calcareous aquarium sand (2:1:1). Dried sphagnum moss is also perfectly suitable.
A large volume of peat helps to limit temperature variations at the root level.