This blog is about growing tropical-looking plants in the Phoenix, Arizona area

August 6, 2013

Strange growth on the top of a sago palm

I received an inquiry recently by someone in Tucson, Arizona, who asked about a "strange growth" starting to grow in the middle of their sago palm (cycas revoluta). If you're seeing this, don't worry, it's perfectly natural. It's a cone.

Although they physically resemble palm trees, cycads are more closely related to conifers (pine trees). And while they don't cone as often or as profusely as your average Christmas tree, they do cone. If you've had a sago palm for many years and haven't seen it cone yet, be patient. It will. The plant has to be very mature before it starts it's reproductive cycle, at least ten to fifteen years.

It's actually quite fascinating, as cycads are either male or female. But you can only tell the gender of a plant from its cone. The one in the photo, by the way, is a male. The female cone is much wider and flatter, so if yours looks like that, congratulations, it's a girl!

Double male cone on a dioon edule cycad
Cycads are very ancient plants, which were on the earth before the evolution of flowering plants, so they don't flower. In fact, it's kind of amazing that these plants survived at all, as they depend on being close to a plant of the opposite sex at the same time that that other plant is coning. There are a few plants like this (dioecious), but not many.

I have two cycads coning right now at The Tropical Paradise, and while it's interesting, I always find it a bit disappointing. To me, it just means that there won't be a flush of new leaves until next year. But while your cycad is coning, take some photos. After a month or so the cone will start to look ratty and start falling apart, so break it off and throw it away. Next year there will be a normal flush of leaves, but expect the cones to come back every couple of years. Life is trying to find a way!

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