South Africa's Cape Provence is one of only five places in the world that enjoys a climate generally classified as Mediterranean. California is another. (The remaining three are a small part of Western Australia, Chile and, of course, the Mediterranean area itself.) If you've ever wondered why we in Southern California have difficulty growing certain plants commonly mentioned in garden books, or those remembered from other parts of the country, it is because our climate is one of the rare and relatively small Mediterranean-type areas.
Most garden plants were discovered or developed in the more-garden-oriented temperate climates, such as our own East Coast, Europe, Japan and much of China. By comparison, very little has come from areas with Mediterranean climates, and what has emerged from such places represents only the tip of the floral iceberg. These areas produce exceptionally diverse plants that have adapted with considerable imagination to summer drought and mild winters.
For that reason, the Arboretum at the University of California, Irvine is specializing in South African plants, an unusually rich flora that has been preserved nowhere else. Under the direction of Prof. Harold Koopowitz, plants are being assembled in a living collection and in a gene bank in which seeds are preserved for future generations. The future of many of these South African plants has been threatened by economic development. Because of similarities in climate, California is a logical second home for their safe-keeping.
For Southland gardeners, the collection is exciting and full of promise. Many South African plants--from gazanias to coral trees--already are important California garden plants, but there are numerous others that should be tried--many of increasing importance because they need little irrigation. Already, the arboretum has produced hybrids of wild gladiolus that are remarkably different from common garden hybrids (one is pictured at left). Modern garden gladiolus were developed from only six wild African species; yet there are more than 150 distinct species of African gladiolus (imagine the possibilities!), of which 57 face extinction.
Bulbs are a specialty, particularly those from the Iridaceae , Liliaceae and Amaryllidaceae families. South Africa is exceedingly rich with bulbs, although a part of the lily family that is well represented here is the unlily-like Aloe clan. The arboretum has 176 species of these succulent distant relatives of our yuccas, 66 of which are threatened.
The gardens are at their best in spring, when plants from summer-dry climates tend to flower. That is when almost all of the bulbs bloom, and most of the other flowers too. In summer, most plants are dry or dormant. However, Saturday, Aug. 17, beginning at 10 a.m., many extra bulbs from the collections at the arboretum will be for sale. Supplies will be limited, but it will be a chance to purchase some lesser-known bulbs that are not available anywhere else. The UCI Arboretum is on a small side road off Campus Drive, across a wildlife refuge from the main campus. To get to Campus Drive, exit to the south off the San Diego Freeway (I-405) on MacArthur Boulevard.