Darlingtonia are carnivorous plants native to Northern California and Southern Oregon and are mainly mountain plants, although they do grow down to sea level near the coast. They are usually found growing along mountain streams in serpentine gravel, in forests under dappled shade near the coast and also in water meadows in the mountains. The common factor in all these locations is constant slow moving cool water, indeed Cobras usually grow near natural springs.
The Cobra Lily has a reputation for being difficult to grow. This article will show you how to grow your Darlingtonia Californica plant successfully.
The Trapping Method
The leaves on a Cobra Lily bear a strong resemblance to a Cobra rearing up ready to strike with its forked tongue flicking out, hence its common name! The leaves are tubular rising up to a puffed hood full of transparent windows, with a circular opening beneath. From this opening the nectar baited tongue appears. It is this tongue that most often lures flying insects, once there they follow the nectar trail towards the inside the trap where the bright light shining through its transparent windows offers a means of escape. Once inside the trap it is almost impossible for the insect to escape due to the curled edge of the trap entrance, similar to a lobster pot. Whilst trying to exit through the translucent windows the insect falls down the tube of the trap, where sharp downward pointing hairs make it a one way trip.
It is best to grow Cobras in quite large pots as they send out runners (stolons) from the roots that form new plantlets at the end once they reach the surface of the soil. Glazed drained ceramic pots work well. Light coloured plastic pots can be used, preferably white if available but never black as it would tend to heat up too much in the sun, Darlingtonia likes its roots kept cool. Always use drained containers. Cobras only need re-potting every two or three years for maximum growth.
Many growers insist that you must grow your plant in pure live Sphagnum Moss for success with Darlingtonia. In my experience this is not the case, I find that a mix of 50:50 peat/perlite or 50:50 supersphag/perlite works well. The important thing is to keep the soil mix airy to help cool the roots.
Stand pots in a deep tray containing 2-3” of rain or distilled water. It is important to water from above with cool water to keep water flowing through the roots and help simulate the plants natural environment and keep the soil temperature down. This should be done at least once a week, daily in hot weather.
Grow your Cobra lily outside in a sheltered partly shaded position. In temperate climates like the UK your plant can be grown outside all year round as they are extremely hardy and frost resistant once established. Can also be grown in a greenhouse near a vent or door to help it keep cool. Growers who live in hotter climates tend to struggle with cobras, but if steps are taken to keep the plants roots cool and not cooking in hot sun it should grow just fine. Some suggest placing ice cubes made from distilled water on the soil surface in hot conditions.
If grown outside your Cobra will catch all it needs, usually copious amounts of large flies and wasps. If grown on a windowsill or in a greenhouse you might want to try feeding your plants dried insects. You can also use fertilizer intended for orchids used as a foliar feed.
The easiest and fastest method to propagate Darlingtonia is from the stolons (runners) they send out. This is best done in early spring before growth resumes. Remove a stolon from the plant once a baby plant has appeared at the end and cut it into sections about an inch long. Ensure each section has a few small roots. Place the sections in a shallow tray of wet live sphagnum moss and partly cover the sections with moss. Cover the tray to ensure high humidity and then place in a bright area out of direct sun. New pitchers will grow from the sections sometimes yielding several plants per section. Don’t separate into individual plants until they each have a good root system. Whilst you can propagate cobras from seed it is VERY slow taking about four years to grow four inches!
Root segments in tray of moss:
Same Cuttings After two Months:
- Darlingtonia californica Wikipedia page
- Botanical Society of America, Darlingtonia californica – the Cobra Lily