Fall is the favored time to plant just about anything in California. The reason is simple--the weather is cooling down and the possibility of rain on the increase, rain that will help out with the tedious job of watering new plantings.
But even if it does not rain, and it has not rained much during the past four years, plants are more likely to survive because they are not subjected to the stress of summer so soon after planting.
In autumn, days are short and nights, at least, cool. Fungus diseases that thrive in warm moist soils are inactive. When you water, it stays in the soil longer and does not immediately evaporate, so young, vulnerable plants are less likely to dry out.
And recent research indicates that the autumn months are the time when roots grow, after the plant has made leaves, flowers and fruit during spring and summer. A plant cannot be considered "established" until the roots have grown out from the root ball into the surrounding soil.
When water is scarce, as it is now, fall planting becomes even more important, because it requires considerably less water to start something now, than in the spring, and any rain that comes along will help out. Instead of watering a new plant every day or two, you can wait three or four days, or even go a week between waterings when the weather cools even more in November.
Even a drying Santa Ana will not dry the soil as fast as a spring or summer sun; scratch the surface and you will find the ground still moist even after a week of the red wind.
Despite the benefits of fall planting, Californians still do most of their planting in spring or early summer, according to the nurseries that sell them their plants, just as if they lived in Boston or Des Moines.
So, one of the new ways with water we should all be adopting is to plant as much as we can in the fall, and save spring and summer for those few things that must be planted then, such as zinnias and tomatoes or subtropicals that might be damaged by winter's frost.
The fall planting season begins in mid-September, when some bulbs, such as freesias and daffodils, and some early annuals, including sweet peas and calendulas, should be planted.
Most other plants, including trees, shrubs, perennials and new lawns, are best planted a little later, in October. November is also a fine time, but the weather begins to cool rapidly by mid-month and this will slow down the growth of spring flowers and bulbs.
Even December is OK, if you can find the time, and during dry years, January and February and early March are preferable to April, May or June. But the autumn months are the best.
Fall is when Mother Nature plants things in California. Following the first rain, up come the weedy grasses and wildflowers. As moisture builds in the soil, shrubs begin growing again and perennials leaf out, and almost everything blooms in the spring, not in summer (there are a few exceptions such as the native \o7 Zauschneria\f7 , which blooms alone in late summer).
Spring-blooming flowers and vegetables that are harvested during cool weather, are usually the first things to be planted in the fall. See the chart for suggestions on what to plant in the fall for spring color or crops.
This fall, with water-saving in mind, you may want to hold off planting things that need immediate watering until the weather cools a little more in October. Then they will need less water to become established.
But bulbs can go in the ground right away and even annual, spring-blooming flowers such as calendulas and pansies can be planted if watered precisely and sparingly, wetting only the ground immediately around the plant (this is a good job for a drip irrigation system).
Ranunculus tubers, which bring forth spring's brightest flowers, only need to be watered once after planting, and then not again until they sprout out of the ground, and this is true of many bulbs. Some of the bulbs that originated in South Africa, such as freesias, ixias, sparaxis and homerias, can almost survive on rainfall alone.
The cole crops, including broccoli, cabbage and cauliflower, need an early start since they are slow growers and bolt to seed at the slightest sign of spring, so they should be among the first planted.
Perennial flowers can also be planted now, though do not expect to see much activity above ground, though they are busy growing a few inches below. Most perennials bloom in spring or early summer, but don't do much growing above ground until February or March. These can wait till late October or November to be planted.
For those planning big changes in the garden, perhaps to a more water thrifty plants, October is definitely the time to get started so plants are well-established by next summer. This is just about the only time you can plant California natives, and most drought-resistant plants do best planted in the fall. But all trees and shrubs and ground covers thrive when planted in the fall.