Did you know that we live and garden in a rare and unique climatic zone? The Mediterranean climate exists in only 2% of the world’s land mass, found in just five regions: the Mediterranean Basin, Chile, South Africa, California, and Australia. Despite being spread across different continents, these areas share a strikingly similar climate—mild, rainy winters and hot, dry summers.
What makes these 5 regions even more fascinating is their location. If you look at a globe, you’ll notice that two are in the Northern Hemisphere and three are in the Southern Hemisphere, all positioned midway between the equator, and the north and south poles. Each one sits on the west or southwest coast of a continent, where cold ocean currents help regulate temperatures. Additionally, subtropical high-pressure systems dominate, preventing summer rainfall and shaping the distinct weather patterns that define Mediterranean climates.
Understanding this unique climate is key to gardening successfully in our region. So, how does it impact the way plants grow—and what does it mean for gardeners? Let’s explore.
Plants that have adapted to dry summer climates have a lot in common. Many are drought-deciduous. They drop their leaves during periods of drought to conserve water—only to sprout fresh growth when moisture returns. Take California sagebrush (Artemisia californica), for example; it loses its leaves under stress but quickly grows new leaves when water is available again. Other plants, like Purple sage (Salvia leucophylla) respond a little differently by producing different types of leaves depending on the season. California lilacs grow thick, leathery sclerophyll leaves with fewer or smaller stomata to reduce water loss. If you’ve ever walked through the native section of a nursery, you may have noticed that many of these plants have upright, grayish green, or whitish coloring, or even hairy surfaces. These adaptations are designed to reflect sunlight and minimize heat stress, allowing the plants to thrive in hot, dry conditions.
In Plant Life in the Worlds’ Mediterranean Climates (University of California Press, published for the California Native Plant Society), Peter R. Dallman describes not only the unique characteristics of Mediterranean climates but also the diverse plant life that thrives in these dry, hot summers. He highlights species from chaparral, oak woodlands, and forest plants that are all well adapted to this rare 2% of the world’s landmass we belong to.
Dallman encourages us to work with, rather than against, the natural conditions of climate, microclimates, and soils. To truly understand and appreciate our Mediterranean climate he suggests exploring local open spaces throughout the seasons. A walk through Briones Regional Park, state parks, or nearby open spaces offers a firsthand look at the resilient plants that have adapted to our Mediterranean climate—perhaps even inspiring ideas for how to incorporate them into our own landscapes.
References:
Calscape, California Native Plant Society
Mediterranean Garden by UC Master Gardener Volunteers of Contra Costa County
Plant Adaptations to Mediterranean Climates, webinar by Dawn Kooyumjian