Dioon edule ‘Palma Sola’

A few weeks ago I visited the Mexican Collection at the University of California Botanical Garden in Berkeley (UCBG). I expected to find all kinds succulents—agaves, yuccas, beschornerias—and I did.

Dioon edule in Mexican Collection at UC Botanical Garden

To my surprise and delight, I also came across several Dioon edule, a cycad species native to the eastern coast of Mexico where it grows in tropical deciduous thorn forests and oak woodlands. Its Spanish name, palma de la virgen, indicates that it is commonly thought of as a palm, but just like the sago palm (Cycas revoluta), it is as closely related to palm trees as a turnip, i.e. not much.

Dioon edule in the landscape
Image source: Wikipedia

I’ve recently become somewhat enamored with cycads, as described in this post. After seeing Dioon edule at UCBG, I knew I wanted one. Even though it is one of the most common cycads, few nurseries in Northern California carry it, especially at this time of year. (I did see one at Green Acres last summer.) eBay to the rescue! I’ve had nothing but good luck in the past buying plants off eBay so I didn’t hesitate to jump on a listing for three Dioon edule for under $30—that’s less than some online nurseries charge for one plant! The seller assured me that these weren’t tiny seedlings, but 5-year-old plants with a caudex between 1½ and 2 inches.

                                                                                                                                             

 

When the box arrived yesterday, I had that famous Christmas-in-July feeling. There’s nothing like opening a box and not quite knowing what you will find inside. In this case, I found three healthy looking plants bursting out of the band pots where they no doubt had spent all of their young lives. The largest plant does indeed have a 2-inch caudex, and the others aren’t far behind.

 

 

I removed one plant from its pot and found mostly roots and very little soil. I immediately repotted them into 1-gallon containers, and I’m hoping that, given enough water and fertilizer, they will be ready for 5-gallon containers by the end of summer. At that point I will decide whether to plant them out into the ground or whether they will remain in containers. The leaves of these cycads look very tropical and there are quite a few places in our garden where they would look great.

 

Dioon edule prefers full sun (but does OK in part shade) and is considered to be quite drought-tolerant. According to Floridata, mature plants have survived temperatures down to 9°F for four days. Other sources claim a cold hardiness of 15-20°F. In either case, our zone 9b winters should be not problem.

 

The three plants I got are actually a form called ‘Palma Sola’. Its leaves are more V-shaped that the species and they take on a bluish cast when grown in full sun. In addition, the entire plant is larger (up to 6 ft.). A&A Cycads calls it “perhaps the most impressive Dioon in the edule complex.” Sounds good to me!