Darlingtonia Californica is an easy and rewarding plant to grow in the right position, but will struggle if it is not in the right place.
Grow in pots (preferably brown or white rather than black to prevent too much root warming) in water trays or saucers in a cold greenhouse or outside.
Darlingtonia does not like to have its root growth cooked during a hot summer. Do not stand plant in a hot conservatory or on hot patios. If grown undercover, keep plant near entrance so it is the coolest position Darlingtonia will grow up to 75cm tall and prefers a sheltered position if grown outside. We have one colonising well in a large bog garden.
Always use soft water, preferably rainwater. We keep ours standing in 2-4cm water from March through October, and then just damp through the winter. There is no need to pour iced water through the pot, if other root cooling measures are taken. We have never used iced water.
Never give any fertiliser through the root system. If the plant is grown in fly free conditions, it is best to feed live insects into the trap during the growing season. Live wax worms and meal worms can be obtained from http://www.globallivefood.com . We find it to be a good feeder by itself, often getting indigestion in the summer months, when they catch many insects very quickly. This causes a brown patch and it is a good sign of a healthy plant. It is difficult to avoid without blocking up the entrance to the trap with cotton wool.
We have had large mature plants outside over winter, down to -13C and have had reports from a customer in the midlands who have had them survive -19C!Small plants and seedlings are not so hardy, and should be over wintered in a cold greenhouse, cloche or cold windowsill. Remove old foliage as it dies down, especially if grown under cover as dead leaves can harbour botrytis. However, this is more common in Sarracenias. It is important that Darlingtonia have a cold winter so that it stops growing and has a rest.
We use a mixture of 6:2:1 Sphagnum peat: perlite: sharp lime free sand. Parts by volume. Darlingtonia will also grow well in pure live sphagnum moss. Re-pot every two years to achieve maximum growth, but will tolerate being left for four years.
Separation of young stolons from around the edge of the parent plant. Division of the main plant. Can also be grown from seed. Sow immediately after harvesting or in very early spring.
Pest and Disease
Watch out for aphids (greenfly). Look on young developing growth, especially early spring growth as they will cause severe distortion or loss of the fangs. Spray with soft soap or a systemic insecticide, as per instructions on the bottle. Always spray in early morning or evening. Thrips are very small blackish insects that cause speckling and silvering on the foliage. You may need a hand lens to see it. Spray with soft soap or a systemic insecticide. Mealy bug are found deep in the leaf axils or tucked on leaf ribs. They are a small white fluffy mass with a pale pink insect within the wool. Very damaging, and will weaken the plant. Spray a systemic insecticide, or dab each insect with a paintbrush dipped in meths. or alcohol.