Plant Highlight: Aeonium simsii
Aeoniums are popular garden plants for mild coastal climates in California. Most of them are native to the Canary Islands, which are part of Spain but located off the coast of Morocco in the Atlantic Ocean. These islands have a Mediterranean climate similar to that of coastal California, which no doubt accounts for their ease of growth here. Being adapted to the winter rainfall and dry summers which prevail in the Mediterranean area, they are in active growth during the winter and rest during the summer months. This holds true even if watering is continued through the summer, as is often the case in gardens.
Aeonium simsii is a species with relatively small rosettes of leaves, but it branches prolifically to form a dense cushion of ground-hugging heads. This makes it resemble the sempervivums of the European mainland, as compared to the generally taller and leggier forms of many of the other species. The diameter of a single rosette of one of the larger Aeoniums may be greater than a clump of dozens of heads of A. simsii. The bright green leaves of Aeonium simsii are strap-shaped with pointed tips. The lower surface of the leaf is marked by many dark-green short lines running lengthwise, and the upper surface may sometimes have a purplish-brown line in the middle. The leaf margins are lined with translucent cilia, giving them a fringed appearance. The inflorescences are of modest size and emerge in spring. They bear flat-topped (or nearly so) clusters of yellow flowers, contrasting with the conical or mounded form seen in many other species of Aeonium.
In nature, A. simsii grows in rocks at relatively high altitudes on the island of Gran Canaria (to over 5000 feet) in the Canary Islands. Because of the altitude at which it grows, it is one of the hardier species. At The Ruth Bancroft Garden, the aeoniums as a group suffered severe damage in the bad freeze that hit California in late 1990, and many were killed. However, A. simsii was a survivor. Its bright yellow flowers create a welcome splash of color in April and May.