Nature at UCSB – Blue Gum Eucalyptus Trees


Melanie Martinez

Co-Science and Tech Editor

If you’re taking El Colegio Road into campus, it’s hard not to notice the lush beauty of the blue gum eucalyptus trees that line the street. Though native to Australia, this tree can be found all over California. Due to the tropical and temperate climates that the eucalyptus tree favors, Santa Barbara is the perfect place for this species to thrive. While being a great addition to UC Santa Barbara’s (UCSB) natural beauty, the benefits of the tree vary from its use as a windbreak to a source of essential oils and planting material.

The eucalyptus stands tall at a maximum height of 165 feet and has a canopy that can extend up to 30-80 feet. The dark gray trunk that stabilizes the tree is attached to thick branches that curve toward the sky. Dark green, sickle-shaped leaves decorate the branches and create a highly desired shade below. These branches and leaves together create a windbreak against the prevailing westerlies of our region. These are winds that occur between 30 and 60-degree latitudes, running west to east

The flowers of the blue gum eucalyptus are quite unique; flowering during the winter and spring, its yellow or white flowers can be seen blooming high in the trees. Rather than common petals, these flowers have thin and long fuzzy stamens. The stamens surround the entire rim of the flower bud and emit a pleasant fragrance. The center of the flower is a dark brown from which either a gray or blue-green fruit capsule grows. The flowers usually bloom clustered close together and tend to resemble dandelions hanging from the tree.

This tree has many other uses beyond aesthetics. The fragrance of the tree is caused by the oil content within the leaves and bark. The oil can be extracted and used for medicinal purposes or as an essential oil that benefits the respiratory system and the diffusion of air

With the increased need to conserve water brought on by California’s yearly droughts, the eucalyptus has been a contributing factor in shaping new planting methods. After cutting down a eucalyptus rather than discarding the tree, its parts can be broken down to make mulch. Mulch is used to retain moisture in the soil and can reduce the amount of water used to water plants. Depending on the mulch’s content, it can also add nutrients to the soil.

The blue gum eucalyptus has quite the history here at UCSB. In the 1870s, many years prior to the groundbreaking of the campus, the land was owned by two brothers. In order to divide their land, they used the blue gum eucalyptus to form natural property lines. Later in the 1920s, rows of drought-tolerant eucalyptus trees were planted as windbreaks. Many of the trees planted back then are still standing on campus, and a few of them can be found near Broida Hall and the lawn by the chemistry buildings.

The blue gum eucalyptus tree holds a rich historical connection to the land we now call home. The trees have seen the creation and growth of UCSB and continue to do so today. Whether that be historically or aesthetically, the eucalyptus is a staple tree that can be seen around campus. Used by many students every day, the eucalyptus tree is a good spot to eat a snack or wait between classes!