How did the Tasmanian Blue Gum Eucalyptus, a tree from Australia, come to dominate the Bay area landscape? The story begins in the 19th century, soon after the gold rush, when thousands of settlers needed wood to build and fuel the city. At that time, settlers were logging oaks and redwood at an alarming rate. Eucalyptus was known to be a fast-growing hardwood, and its ability to soak up water could reduce swampy land. San Francisco, fast- growing and surrounded by muddy tidal flats, embraced the exotic species.
Central and Southern California, naturally grassy with few trees, followed suit. The state legislature passed the California Tree Culture Act in 1868, paying landowners $1 per tree to plant and nurture trees for a minimum of 4 years. Over the next 40 years Californians, encouraged by the government and by promoters, planted eucalyptus seedlings by the thousands. The tree would provide shade, windbreaks, railroad ties, antiseptics, fuel, fencing, and more. As the tree soaked up water and created tillable land, it also diminished a breeding ground for mosquitos and helped reduce malaria.
Some notable examples:
- Leland Stanford planted 700 trees in a mile-long row at Stanford University as a promenade called Governor’s Row.
- The US army planted eucalyptus at the Presidio as a windbreak and as a way of distinguishing the base from surrounding areas.
- Adolf Sutro planted a forest of eucalyptus on Mt. Parnassus (now called Mt. Sutro) for a public pleasure garden and to take advantage of a tax break for forested areas.
- Central Pacific Railroad planted 1 million eucalyptus in the San Joaquin Valley for railroad ties, poles, and posts.
- Writer Jack London planted over 40,000 seedlings on his ranch in Sonoma, hoping to sell the wood for profit in a few years.
- Frank Havens, a developer, planted 8 million trees in a 14 mile strip from Berkeley to Oakland.
- Abbot Kinney, state forester, promoted the tree and distributed free seeds across the state.
Eucalyptus trees flourished in California’s mild climate, but the harvested young wood proved a disappointment. Prone to twisting, cracking and hardening, the wood was unsuitable for furniture or railroad needs. When oil replaced wood as a source of fuel, the demand for eucalyptus declined. The eucalyptus bubble burst, and the trees were left for shade, shelter and bird habitat.
Today environmentalists admit the invasive nature of the eucalyptus tree and its hazards: its instability and its flammability. Yet they recognize that the tree has become home to many birds, animals and the endangered monarch butterfly. The park service manages the eucalyptus forests to reduce the hazards but preserve the trees by removing tree limbs, surface fuel, thinning trees and removing stumps.