While many regions experience a sudden drop in temperature and vibrant autumn leaves, some areas recognize up to six seasons, characterized by more subtle changes. In these locations, fall arrives with slanted light, longer shadows, and breezes that feel both warm and cool.
As interior valleys cool down, the marine layer gives way to mild, sunny days along the coast, creating some of the best weather of the year in September and October. In gardens, plants begin to bloom again, leading to the expression “Second Spring.”
Why Plant in Fall?
In regions where temperatures drop significantly and the ground freezes, planting becomes impossible during autumn and winter. However, in milder climates, fall is an ideal time to plant. While tomatoes and other warm-weather annuals must wait for spring, there are many advantages to planting trees, shrubs, perennials, and native plants in the fall.
Less Transpiration: Shorter daylight hours in autumn mean less moisture loss from leaves, allowing plants to retain more water and experience less stress.
Warm Soil: The soil remains warm in the fall, promoting rapid root development. When winter rains arrive, these roots can better utilize moisture. By spring, the roots will be prepared to support the growing plant, helping it withstand higher temperatures and reduced moisture during summer.
In contrast, spring planting offers limited time for root development before temperatures rise. This often requires more frequent watering, which, combined with warmer soil, can lead to soil-borne fungal diseases.
What to Plant
Fall is the perfect time to add trees, shrubs, native plants, and perennials to your landscape. It’s also the ideal season to plant bulbs like tulips and daffodils, allowing them ample time to bloom in spring. Don’t wait until you harvest your last tomatoes to start cool-season vegetables. Crops like broccoli and cauliflower thrive with some early warmth and can yield a surprising harvest.
Additionally, autumn is the time to plan for spring wildflowers. Scatter seeds just before the first rains, and once the ground is moist, the seeds will germinate over winter, ready to bloom in spring.
Time to Divide
Fall is also the season to divide and move perennials that clump or have multiple stems above ground. Plants like Heuchera, Coreopsis, Chrysanthemums, Scabiosa, and Penstemon can be divided to stimulate growth, encourage blooming, and increase your plant stock at no cost.
Shopping for Color
Autumn is the best time to shop for trees and shrubs with colorful fall foliage. Here are some options that thrive in our area:
Roger’s Red Grape (Vitis “Roger’s Red”): This fast-growing, deciduous grape vine is a hybrid of native California grape and wine grapes. It covers fences or arbors quickly and showcases brilliant red leaves in the fall. It requires little water, tolerates various soils, and attracts birds with its small, seedy grapes. Prune in spring to control growth.
Crape Myrtle (Lagerstroemia indica): This bush or small tree offers vibrant blossoms in summer and stunning fall foliage that transitions from green to orange, red, and gold. Crape Myrtles are low-maintenance, drought-tolerant, and thrive in well-drained soils with plenty of sunlight.
Western Redbud (Cercis occidentalis): A versatile California native, the Western Redbud features deep pink blossoms in spring and heart-shaped leaves that turn red and yellow in fall. It can grow as a large shrub or small tree, reaching up to 20 feet high and wide. This drought-tolerant plant thrives in a Mediterranean climate and adapts well to various soils with adequate drainage.
By planting in the fall, gardeners can take advantage of the season’s unique conditions, ensuring a thriving landscape for years to come.