Aeoniums, a Canarian who feels at home in Marin

We hear the message to conserve water a lot these days, and it’s no wonder with another year of drought stressing our state. Water conservation is a principle of environmentally responsible gardening and the North Marin Water District and the Marin Municipal Water District encourage water conservation through their rate tier systems. No wonder interest in succulents is at an all time high.

My garden is full of Aeoniums, which are native to the Canary Islands and North Africa, and thrive in Marin.

There are about 35 varieties of Aeoniums, and they all grow in two ways: either low-growing or those that use a short trunk.

The distinctive geometric circular leaf rosettes typical of all Aeoniums can be as small as 4 inches or as wide as 2 feet, depending on the variety. Rosette colors range from shades of green to purple to almost black.

Aeoniums generally like full sun to partial shade in the milder parts of Marin, but will need some shade in the warmer parts of the county. These subtropical succulents like good drainage.

Photo by James Campbell

Aeoniums are succulents that come in all sorts of sizes.

For me, the foliage is the main attraction of Aeoniums. Their oblong leaves resemble large fleshy flowers. They have true flowers, but most Aeoniums are monocarpic, meaning the parent plant dies after flowering, with offshoots of offspring that may live on.

Aeoniums are super easy to propagate. I just broke off a piece with a rosette from the parent plant and planted it in the ground where I want a new plant to grow.

My garden must have a climate similar to the Canary Islands as my Aeoniums have naturalized and grown wherever the seeds have spread.

Due to their shallow root systems, Aeoniums are not drought tolerant like most succulents, but they go dormant during the summer months. In my shady garden, they only survive thanks to winter rains and are not irrigated. This means that I get two different looking gardens. In winter, the garden looks lush and green, but in summer, the leaves curl and shrink and look more like a dry garden.

During the winter months in Marin, the Aeoniums are lush green and plump.  (Photo by James Campbell)

Photo by James Campbell

During the winter months in Marin, the Aeoniums are lush green and plump.

Aeoniums store water in the fleshy leaves of the rosette to survive the hot, dry regions from which they originate. Like other succulents, Aeoniums avoid desiccation by only opening their stomata at night. Stomata are the leaf cells that release oxygen and absorb carbon dioxide. Aeoniums convert the carbon dioxide they absorb at night into a four-carbon organic acid that is used during the day for photosynthesis. The term for this is crassulacean acid metabolism.

The leaves we are most familiar with are relatively flat with mostly visible vein patterns. The leaves of succulents, such as Aeoniums, are plump and filled with precious water. Maintaining efficient photosynthesis requires an evolution of leaf vein structure from a two-dimensional pattern to something best described as three-dimensional.

The name Aeonium comes from the ancient Greek word for ageless. This is a testament to their ability to keep producing new plants and last forever. So try some of these whimsical succulents in your garden. Your water bill will thank you.

Sponsored by UC Cooperative Extension, the University of California Marin Master Gardeners provide scientific and research-based information to home gardeners. Email your questions to [email protected] Attach photos for plant pest or disease inquiries. The office is closed for visits without an appointment. Subscribe to the Flyer, UC Marin Master Gardener’s free quarterly electronic newsletter, at marinmg.ucanr.edu