Darlingtonia is native to the mountains of North California and Southern Oregon in the USA. It is is the only species in its genus, though its trapping mechanism is identical to that of Sarracenia. Under the correct conditions the pitchers can grow to a height of 1 metre, though this is rarely achived in cultivation.
Darlingtonia's prefer an acidic compost without the addition of any nutrients, a good base compost would consist of 4 parts moss peat to 1 perlite.
Silver sand can be used instead of perlite or as an addition to the base mixture to improve drainage.
Darlingtonia's will grow in a pure moss peat mixture, however with this mixture ensuring the compost remains moist can be a problem.
Darlingtonia thrives in good light and ventilation, preferably with high humidity, however providing the compost is kept wet (only damp during the winter) it is able to withstand dry, direct sunlight conditions found in a typical conservatory or greenhouse. If the plant is to be kept outside, then provision should be made to ensure the compost is kept moist all year round. This may seem obvious during the growing season, however winds during the winter can be extremely dry and if care is not taken plants can easily be lost due to lack of water during this period.
Aphids will be found to affect the immature pitchers as they are developing, resulting in a deformed pitcher, usually incapable of catching any insects. Control is easily achieved by any of the usual methods for this pest, spraying with a systemic insecticide usually being the easiest method.
Darlingtonia are susceptible to attacks by vine weevil larvae, these will eat the roots, usually the first visible sign of an infestation is the pitchers starting to wilt and die. Examination of the plant will highlight it to be loose in its container. Control of the adult beetle and larvae can be achieved by either biological or chemical methods, the choice being down to the individual and their views on the use of chemicals.
Wasps can cause damage to the pitcher itself by eating their way through the walls of the plants after they become trapped inside. This only affects the plant from an aesthetic point of view, though if the hole is large enough it will allow further insects that are caught an easy means of escape.
Darlingtonia has proved remarkably resistant to any disease, even in plants that have become crowded and contain dead pitchers, Botrytis Cinerea (grey mould) has not become a problem. Poor drainage of the compost or the use of alkaline water being the usual reasons for the roots and rhizomes to fail.
Propagation is best done by division of the many rhizomes that are produced by the parent plant. Removal of a two or three year old plant from its pot will reveal numerous rhizomes, some will have probably circled the pot two or three times before producing another plant. The young plants (with roots) on these rhizomes can be removed from the parent plant using a sharp knife and potted up in the usual compost. Care should be taken to ensure the compost is kept moist at all times, other than that no special attention is required.
As with almost all carnivorous plants Darlingtonia's require an acidic water, free from any chemicals, rainwater being ideal. They require a moist compost at all times, this is most easily achieved by standing the pots in a water filled tray. Generally speaking, water to a depth of 1.5 to 2 cm should be sufficient through the spring and summer months, this can gradually be reduced through the autumn, whilst through the winter it is only necessary to water the compost as and when required.