Darlingtonia californica Care

The cobra plant, Darlingtonia californica, is an awesome plant in person, and the second most requested plant from our customers after the Venus flytrap. When fully grown, its pitchers can tower 3 feet tall with heads the size of fists! But we'll be straightforward about it: Darlingtonia is a mountain plant that requires cool nights (in the 50s or colder). If summer nights are too warm, the plant will develop health issues and likely die. Cool nights is not an option. It's a requirement for this plant.

If you’ve successfully grown Sarracenia and other outdoor carnivorous plants in the past, you will enjoy the challenge of Darlingtonia. If you’re new to growing carnivorous plants, gain some experience with other plants first. Get a handle on the basic elements of cultivation by reading The Ultimate Carnivorous Plant Guide for Beginners to learn more about growing some of the easier and more common plants in cultivation.

Range
Darlingtonia is native to remote mountain streams in Southern Oregon and Northern California. A few smaller patches grow in lowland streams along the Oregon coast, but the majority reside in the mountains. Regardless of its natural habitat, all populations experience cool nights during the summer months.

Where to Grow
Darlingtonia grow best outdoors as a container plant on a sunny deck or patio. You may also grow it in a pond or fountain with flowing water, but keep the crown of the plant from being submerged. Because of its specific soil requirements, avoid planting it in the ground.

Sunlight
Darlingtonia requires partial to full sun (4 or more hours of direct sunlight) for vigorous growth during the growing season. Although Darlingtonia can grow in some shade, avoid full shade. When in doubt, give more sunlight.

Heat Tolerance
Darlingtonia can withstand extreme heat. In its native habitat, Darlingtonia will experience temperatures of 104°F during the summer. However, if daytime temperatures rise above 90°F, nighttime temperatures need to drop significantly, in the 50s or colder. Cool nights are essential for the overall health of this plant.

Soil
Over the years, we've experimented with a variety of soil mixes. In the end, we found that live sphagnum moss is much more reliable than peat-based mixes. So, we now recommend live sphagnum moss as the preferred medium. Perlite can be used to line the bottom of your pot to reduce the amount of sphagnum moss needed.

Avoid using peat moss, potting soil, gardening soil, and forest compost.

Water
When using live sphagnum moss as your growing medium, you will need to use water with a very low mineral content, less then 50 ppm of dissolved minerals. Keep the moss wet at all times by top watering frequently or setting your pot in a shallow tray of water.

Pots
The ideal type of pot for a Darlingtonia is short and wide. Darlingtonia have short roots, so the container doesn’t have to be tall. However, because they self-propagate via long underground stolons, the pot needs to be wide. Because of their cold winter dormancy requirements, ceramic pottery, especially unglazed pottery, may be unfeasible as it tends to crack during freezes.

In our experiments, we discovered that plastic cat litter pans worked very well. They're wide containers than they are deep, with enough depth for Darlingtonia roots and enough width for the plant to comfortably spread. We used brand new pans from a local discount store. Along the sides of the pan, we punched small 1/4 inch holes about ½ inch from the bottom for drainage. Technically there will be sitting water ½ inch deep at the bottom of the pan, but as the surface area is ample enough and the soil relatively shallow, water will evaporate much faster. For a while, we grew the majority of our mother plants in these pans. If plastic cat litter pans are too unsightly, consider using wide plastic garden bowls.

Winter Care
Your plant will stop growing in early fall, and some pitchers will turn brown. These are signs that your plant will soon be dormant, a similar process when a rose bush goes dormant and drops its leaves in fall. While dormant, your Darlingtonia can withstand episodes of overnight frosts down to 20°F. If daytime temperatures are projected to rise above freezing, you don't need to protect it from these overnight frosts. However, protection is required during prolonged freezes to prevent dehydration or freeze drying, regardless of USDA zone. Covering your plant with a tarp or black plastic sheet will be sufficient if the freeze is expected to last for a week or less, which is typical for USDA zones 7 and 8. Otherwise, mulch may be required if you live in a region where freezing temperature is a way of life, such as in USDA zones 6 and colder.

Need more information about winter care? Watch the Volume 1 playlist and monthly videos. Our digital download, The Ultimate Carnivorous Plant Guide for Beginners, is also a fantastic resource if you are new to growing plants. We share how various elements – sunlight, water, soil, and humidity – affect plant growth and what to pay attention to during winter dormancy. Visit the website to access these resources.