Arboretum All-Stars: Great Plants for Central Valley Gardens

Heuchera ‘Rosada’. Photograph by Nikhil Joshi

Like most of the state, California's Central Valley has a mediterranean climate, with hot, dry summers and cool, wet winters. Compared with coastal California, however, where most of the state's horticultural resources are located, the Central Valley experiences greater extremes of heat, cold, and drought. For example, the record low temperature at Davis is 12° F, record high is 116° F, and average annual rainfall is only seventeen inches. Many areas of the valley also have heavy, clay soils, and the ground water used for irrigation in much of the valley contains high levels of bicarbonates. These bicarbonates, when applied to neutral or acid soils, raise soil pH over time, making the soil more alkaline, which restricts or eliminates the ability to grow many kinds of plants, especially acid-lovers like azaleas.

The Central Valley is the fastest-growing region of California; its population is expected to double within the next fifteen years. Many new valley residents are moving from California's coastal regions. They may enjoy less crowding, lighter traffic, an...