Cold, dry, cloudless days make working in the garden a pleasure. From the upper hillside overlooking the rose garden, the early-morning activities include watching the resident otters out for a meal and a little play. This amphibious mammal, known for its grace and playful nature, can be spotted eating fish from a perch on the pond filters and delighting visitors. The river otter’s fur consists of two layers — a coarse, waterproof outer coat and a softer layer that keeps the animal warm. While in the water, the coat is covered by a silvery sheen of air bubbles that cling to the outer hairs.
In the garden, our tough California native plants are not fazed by a lack of water or by cold temperatures. One of the garden work horses — Rhamnus californica, or California coffeeberry — is at its peak during the autumn months, when its deep red berries begin to blacken. Now is the time when the minute yellow-green starlike flowers, which are small and insignificant, shine against the brilliant ruby-colored stems of this evergreen shrub. It is amazing that such tiny flowers could produce the beautiful berries that are quite prominent throughout the summer months.
The pale green fruit ripens as the heat of summer intensifies, turning eggplant purple and then jet black — hence the name coffeeberry. It is a favorite of quails, thrushes, robins, finches, towhees, thrashers and jays and is a great wildlife-habitat plant. The leaves appear waxy, and their edges curl during the heat to conserve moisture.
California coffeeberry is a member of the Rhamnaceae (Buckthorn) family, which includes approximately 900 species of mostly trees and shrubs. The name Rhamnus californica recently was changed to Frangula californica; however, nurseries are more likely to know it by the former name.
Two other native family members include Rhamnus crocea, spiny redberry; and Rhamnus ilicifolia, holly-leaf redberry. California coffeeberry’s native habitat is widespread throughout the state, which is one reason it does well in a variety of garden settings. Ranging from the coast to the inland valleys, it can tolerate inland heat or the cool coastal breezes. In the garden, it combines well with toyon, sages, ceanothus and other plants that like dry conditions. It makes a great screen or hedge, and it has few diseases or pests, though with poor drainage it can be susceptible to water mold. It does not mind pruning and once established, does well with little or no summer irrigation.
This wonderful California native shrub is growing in the East Bay Municipal Garden, but the best display can be found in the Diablo Ascent Garden, behind the bronze eagle. This cultivar, Rhamnus californica ‘Eve Case,’ has the fattest berries.