Hawaii Kai resident Karl Seff has been infatuated with succulents since first discovering them nearly 50 years ago.

The first ones he ever stumbled upon were flowering sedums growing at the edge of concrete slabs in a desert in San Fernando Valley, Calif. He found it amazing that the plants were growing on bare, rocky dirt with only a bit of rainwater runoff.

"We gathered some up like treasures and took them home," he said. "Some died, some didn’t. We learned and so it began."

Since he moved to Hawaii in 1968, Seff has been a member of the Cactus & Succulent Society of Hawaii, an independent affiliate of a nationwide group dedicated to education, environmental protection and preservation of the plants.

His backyard is a miniature botanical garden of its own showcasing succulents — plants with thick, fleshy leaves or stems that retain water in arid climates and soil conditions.

Cactuses are succulents, he explained, but not all succulents are cactuses.

Perhaps one of the most well-recognized succulents is the jade plant (Crassula ovata), which Seff has in pots all along the rock stairway in his yard.

Seff, 76, is a professor emeritus of chemistry at the University of Hawaii at Manoa. He holds a Ph.D. from the Massachusetts Institute of Technology and did postdoctoral work at the University of California at Los Angeles — when he first discovered sedums — before joining the faculty at UH.

Just what is it about succulents that fascinates him?

"First of all, they thrive with relatively little care," Seff said. "They’re fat and juicy and have unusual shapes."

The rock retaining walls in his backyard made the perfect landscape for Seff’s diverse collection of succulents and was one of the reasons he bought the property in the mid-’80s.

In total he has a half-acre of land behind his home but uses only a portion of it for gardening. Within the terraces of the retaining walls, he laid down a layer of weed-blocking fabric covered with approximately six inches of red cinder.

This is where he’s carefully planted his succulents, along with labels to identify each one. He does not have to water them, as the plants are pretty much capable of surviving on their own with a little fertilizer.

Looming above the other plants is a dagger cactus (Stenocereus griseus), which has grown to about 30 feet tall. He planted it from a pot when he first moved in. There are also agaves, ponytail palms (Nolina recurvata) and a cluster of small, cylindrical Mammillaria angelensis, which create a tableau of textures in varying heights and shades of green.

Potted succulents also line the wall behind his swimming pool, including one of his favorites: the Gasteria doreeniae. Last summer, Seff met the botanist who named the plant at a conference in Austin, Texas.

Seff jokingly says his garden rivals the Koko Crater Botanical Garden just a mile away, which has many of the same plants. As a matter of fact, he donated some of his golden barrels (Echinocactus grusonii) to the city garden.

He collects many of the plants from nurseries around the world, sometimes making friendly plant exchanges with curators of botanical gardens in other states. He brings them back in his suitcase, as long as they are allowed in Hawaii.

Others come from exchanges with members of the Cactus & Succulent Society of Hawaii, which meets once a month.

Despite the relatively easy care and maintenance, growing a succulent garden comes with its share of challenges. He says he learns through trial and error what works best for each plant, whether it’s more or less sun, water or fertilizer.

"Most cacti and succulents die from overwatering," he noted. "Let ’em suffer a little; that’s normal for a desert plant."

On average he spends two hours per week replacing dead plants, transferring keiki plants out of a crowded pot or doing rock and cement repairs. On weekends he enjoys taking note of growth or blooms.

The rewards for any gardener are when one of the plants establishes itself and thrives.

"It is most rewarding when a plant takes hold and grows, develops good roots and has keiki, blooms and gets bigger and bigger," he said.

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ON THE NET:
» Learn more about the Cactus & Succulent Society of Hawaii at cssh.angelfire.com.

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