By Angela O’Callaghan
Many desert landscapes contain a tropical plant, the cycad, but you have probably heard it called “sago palm”. Only the king cycad and the dioon are usually found. While not identical, they have similar habits, so knowing about one will be useful for the other. The sago palm, Cycas revolute is the most common. Other members of the group are found only in the wild, and in real danger of extinction, but landscape varieties are safe. Cycads are ancient; there were dinosaur food in prehistoric hot, steamy conditions! In the wild some individuals are 1,000 years old! They grow very slowly even they originated, the areas that have rainfall and acid soils.
Cycads look sturdy, and can be great specimen plants – under good conditions they can reach ten feet tall and six feet wide. The fronds look feathery; some even resemble ferns. When the leaves first open, they unroll, similar to ferns. But – like so many other local plants – their tips are spiky.
The leaves grow in a tight spiral around the trunk. Like other conifers, they make no flowers. When it is time to reproduce the female plant develops a big, round center cone – very different from palms. If the cone gets pollinated, seeds develop, to produce new cycads. The male plant produces a different shaped cone.
These plants are more closely related to pines and firs –although they look much like palms– the rough trunk, the leaves (which are also known as fronds) – that one might expect them to behave like palms. But this is not a palm, and if treated like one, it suffers.
Many resources, especially on the internet, say cycads prefer full sun. That may be true, but Southern Nevada’s full sun is intense, compared to other areas. These plants respond well when they get several hours of bright light, but if they receive full sun all day in this area, the leaves become damaged. They become sunburned, or more precisely, t sun-bleached, and the tips of the fronds will begin to curl.
Still, they can survive with a little extra effort. Like many other non-native plants, cycads cannot obtain and utilize essential nutrients from unamended local soil. Southern Nevada’s soils are alkaline, while most of the world’s are acidic. Try lowering the pH with soil sulfur, and add compost to enrich the planting bed. In addition to sun scald, poor drainage will definitely cause sago to suffer. Have you heard that a thousand times already? This is yet another plant that will not tolerate “wet feet”.
These are not palms, no matter what the common name is. They do best if they get some protection from our intense sunlight – which is not saying to put them in full shade. When you first put in a cycad, sure the soil has good drainage. You can get information on testing the drainage by calling the Master Gardener help line. Amend the soil with compost. Rememberto give them enough water, especially right after planted. Once established, they prove to be reasonably drought tolerant, a good addition to a desert landscape.
Dr. Angela O’Callaghan is the Social Horticulture Specialist for Clark County Cooperative Extension. Contact her at firstname.lastname@example.org or 702-257-5581.