THE COASTAL GARDENER:

Most casual gardeners probably don’t know the difference between an Aloe and an Agave. They’re so similar, even expert gardeners often have to look twice before offering an opinion. Both are succulent plants that feature large, thick, tapering, pointed leaves. They both like sunshine, are simple to grow and don’t require much attention from their owners. Hence, both are popular in our coastal gardens.

When pressed about Aloes, most people think of the medicinal species, Aloe vera. Extracts from Aloe vera leaves appear in thousands of beauty, medicinal, skin and hair-care products. Aloe vera is a fine species, but it no more defines an Aloe, than a guppy would define a fish. The word Aloe refers to about 400 species and countless hybrids, varying from wiry, creeping, vining plants, like Aloe ciliaris, to stout 20-foot trees, such as Aloe bainsii. But most Aloes in local gardens are small- to moderate-sized clumping varieties.

Aloes have been in our Orange County gardens for more than a hundred years, but they are currently going through an explosion in popularity. It seems everyone now has an Aloe or two somewhere in their garden.

Aloes belong to the family Liliaceae, which contains such diverse plants as Alstroemeria, Easter lilies, onions, mondo grass, agapanthus and tulips. Each species of Aloe varies in the degree of heat, drought or moisture it tolerates. Even seasoned gardeners confuse Aloes with Agaves. Both fill similar needs in a garden, providing supreme elements of form, structure and drama wherever they are placed.

But Aloes and Agaves are really quite different and offer an insight into the paradox of plant diversity on our planet. Aloes and Agaves are a classic example of a phenomenon known as convergent evolution, whereby unrelated organisms evolve independently, but with similar traits due to having to adapt to similar environments. Aloes occur only in Africa, while Agaves are only from the America’s. They never saw each other, nor did they ever have a common parent. But on both continents both evolved in similar environments — long periods of drought, high summer heat and nutrient poor soil. Although a continent away from each other, both appear surprisingly similar and fill the same ecological niche.

Convergent evolution is an interesting topic. Ants and termites are another example of the same principle. Both have similar lifestyles, look similar and even have similar social networks. However, ants are descended from wasps, while termites appear to have descended from cockroach-like insects.

Aloe plants produce a rosette of leaves that vary in size and color with the species. Most types remain ground-hugging all their lives and produce offsets, which are sprouts that appear at the base of the stem or in conjunction with surface roots.

To propagate an aloe, simply separate one of these offsets with as much root material as possible. Place it in a pot of fast draining cactus mix and water it sparingly. Within a few months the new little plant will have filled the pot with roots and be ready to plant into the garden.

In Orange County, Aloes bloom in winter or early spring. Most are in full bloom right now and are easy to spot in gardens. They produce long stems that arise between the leaves. The size of the spike can be quite large and spectacular and the flowers quite showy, usually in bright tones of red, orange, gold and yellow, or in any combination of these colors.

The arboretum at UC Irvine has a large collection of Aloes, most of which are in full bloom right now and worth seeing. The plants here are large and mature, many planted more than 30 by my friend Harold Koopowitz, who was the director of the arboretum for more than 20 years. At one point the arboretum had amassed an impressive collection of more than 130 Aloe species, although I suspect there are now fewer. Nonetheless, this is a great time to visit the arboretum, see different Aloes in full bloom or just watch the Allen’s and Anna’s hummingbirds dash from flower to flower.

The UCI Arboretum is located at the corner of Jamboree Boulevard and Campus Drive and is open Monday through Sunday, 9 a.m. to 3 p.m. Admission is free.

ASK RON

Question: I want to plant tuberose, but haven’t been able to find any in the nurseries. What gives?

Matt

Costa Mesa

Answer: Tuberose (Polianthes tuberosa) are sub-tropical plants, originating in Mexico and portions of Central America, although no wild plants now exist. They are best planted from dormant tubers, which are similar to bulbs. The optimum planting time is about March in Orange County, with flowering in late summer. Nurseries should be receiving the dormant rhizomes within the next two or three weeks.

ASK RON your toughest gardening questions, and the expert nursery staff at Roger’s Gardens will come up with an answer. Please include your name, phone number and city, and limit queries to 30 words or fewer. E-mail [email protected], or write to Plant Talk at Roger’s Gardens, 2301 San Joaquin Hills Road, Corona del Mar, CA 92625.

RON VANDERHOFF is the Nursery Manager at Roger’s Gardens, Corona del Mar