Garden Detective

Garden Detective: Sago flowers prompt question: Is it male or female?

I have a sago palm in my back yard that is over 20 years old. It is planted in the ground in full sun and seemingly is doing real well. Each year around June, it usually sends out a cluster of new fronds that numbers about 20. Last year, something different happened. It only sent out two new fronds and the remaining center began swelling. I wondered if I have an alien possessing my tree. It looked like it might be a flower or seed pod developing, but I really don’t know. Can you help me?

– Larry Reagan, Sacramento

According to UC master gardener Carol Hunter, your 20-year-old sago palm ( Cycas revoluta) has a male cone that is just starting to develop. The female flower (or megasporophylls) is a round, somewhat flattened globe in the center of the plant.

Plants of both sexes must be within fairly close proximity for seed production to occur. Sago palms can be propagated with seed that has been fertilized as well as by transplanting “pups” that grow out from the base of the plant.

There is a University of California Publication 8039 that discusses care of the sago palm (find it at Or you can get a copy by mail. Send a self-addressed, stamped, business-sized envelope to: EHN No. 8039, UC Cooperative Extension, 4145 Branch Center Road, Sacramento, CA 95827.

Is this a female flower on my 30-year-old sago palm or what? I’ve enclosed a photo.

– Pat Self, Fair Oaks

According to UC master gardeners Carol Hunter and Timm Johnson, your picture of your 30-year-old sago palm shows a mutation of a male cone. It is not a female flower.

Sagos, interestingly, are not really palms. Although their appearance resembles that of true palms, they are cycads and have an unusual reproduction process that places them somewhere between ferns and flowering plants. Cycads are dioecious, meaning there are separate male and female plants. So a male plant will never produce a female flower.

A living fossil, sagos have changed little in 60 million years. Sagos are relatively easy to grow once they are planted in the landscape and have very few pest problems. They are susceptible to stem rots under conditions of excessive irrigation and poor drainage and aeration. Scale insects and mealy bugs can sometimes be a serious problem.

Sagos also succumb to sunburn under high temperatures and intense light conditions. While they will tolerate full sun, they look better when grown in partial shade.

Sagos planted in good garden soil do not require much fertilizer. They have only one or two flushes of growth a year. Heavy nitrogen applications are not needed. Generally, the best results can be obtained with the use of a slow-release fertilizer or products such as blood meal or bone meal, which decompose slowly.