Autumn is a time for planting partly because it is when many plants are beginning their winter dormancy. They are, or will soon be, less active than they would be at any other time of year. Some may not start to grow again until after winter ends. Others will want to secretly disperse their roots through the rainy winter weather, while merely appearing to be dormant from above the soil level.
That is why autumn is also the best time for division of many types of perennials. Such perennials should be adequately dormant to not be bothered by the process of getting dug and divided into smaller parts, then replanted. They actually prefer to get it done sooner than later, so that they can slowly disperse their roots through cool and rainy winter weather, and be ready to grow in spring.
Divisions is often done to renovate bulky perennials that have become overgrown, shabby, or too crowded with their own growth to bloom well. Some of the more vigorous perennials may benefit from division for renovation every several years or so. Many complaisant perennials may never benefit from division. Of these, some might be divided merely for propagation of more of the same.
Japanese anemone, bergenia and other perennials that bloom in autumn and winter should get divided later, after bloom. Like perennials that get divided now, they tend to recover and efficiently disperse roots before spring. However, they may need to be watered a bit more than typical if the weather gets warm and dry early next year. Their schedules do not coincide with local climates.
Lily-of-the-Nile, African iris and New Zealand flax can be divided into individual shoots, even if a few shoots get planted together in clumps. Entire plants do not need to be dug if it would be easier to merely pluck a few outer shoots from the perimeters of congested parent plants. Black-eyed Susan and Shasta daisy can be divided into clumps of several dormant basal rhizomes and roots.
‘Pups’, or sideshoots, of agaves and some types of yuccas can be carefully pried from their parent plants without disturbing them.
There have been only three hints at precipitation since last spring.
Mild climates allow more flowers to bloom through autumn and winter here than in most other parts of America. That is why cool season annuals like pansies and violas are so popular. Cyclamen can be planted now too. None will be obscured by snow. By the time cool season annuals start to fade, warm season annuals will be replacing them. There is something to bloom in every season.
Every living thing in our gardens came from the wild somewhere. A few plants might be natives trying to adapt to synthetic landscapes. Some might be from similar climates. Some are likely from very different climates. Even houseplants came from the wild somewhere in the World. Regardless of their respective origins, in home gardens, all plants want to behave as they would in the wild.
Mild autumns and arid summers keep chrysanthemums on a different schedule here than in most other regions. They can get planted in spring to grow through summer and bloom through autumn; but because they can take a bit of work, they are more often planted while blooming in autumn. Although commonly grown as autumn annuals, they are perennials that can regenerate next spring, grow through summer, and bloom even better the following autumn.
To those who do not enjoy gardening, the process of planting dormant bulbs must seem to be blatantly unproductive. Those of us who know what we are doing are so dutiful to select the bulbs we want, only to bury them in shallow graves in the garden, with nothing to show for all the effort. Knowing that the bulbs are buried at specific depths and orientations makes them no more exciting.
Okay; so this is neither the first, nor real autumn foliar color. It just happened to be convenient for me to get a picture of. Someone left this unfortunate Japanese maple right outside on the driveway a few years ago. It colors early from uncomfortable exposure to late summer warmth. The picture below is even more colorful, and was from even earlier in the year, last August.
As the name implies, ‘annuals’ need to be replaced ‘annually’. What is worse is that they do not even function for an entire year, but only for a specific season. Cool season annuals mostly work from autumn to spring. Warm season annuals mostly work from spring to autumn. Calendula is a popular cool season annual that may not last even that long, since it can mildew half way through winter.