Cobra Plants (Darlingtonia californica) Growing Tips
Sun: They appreciate lots of sun, like Sarracenia, but in order to avoid overheating in cultivation you may have more success growing it in morning sun only or filtered all day sun. Shade the pots if possible to keep the solar heat at a minimum.
Water: Use the tray method, keeping the soil damp to wet year round. Keep the soil cool by watering with cold water, (refrigerated water is quite helpful on warm summer days).
Temperature: Very winter hardy and can take temperatures down to 15 degrees they are, however, very sensitive to heat especially in the roots. Ideal root temperature would be 40-55 degrees. Warm roots can kill them quite rapidly.
Dormancy: All Darlingtonia require a winter dormancy starting in October and ending in February. Many of the pitchers will turn brown and die back during this time. Leave them outdoors in full sun, sitting in distilled water during this period. If you live in an area that snows; over winter them indoors on a sunny windowsill in an unheated room or garage. Still sitting in full sun and distilled water.
Soil: The best mix for Cobra plants is three parts New Zealand long-fibered sphagnum moss to one part pumice or lava rock. Another good mix is two parts lava rock, and or pumice to one part peat. Basically the mix should be airy and the rock ingredients will help cool the roots. Live sphagnum makes an ideal media as well.
Fertilizer/Feeding: If grown outdoors, they will catch all of their own food. MaxSea fertilizer can also be applied, once per month, to the leaves and pitchers of the plant. Avoid pouring through the soil.