Autumn is for more than planting. It is when most of the aggressive pruning gets stared. It might be the best time to work with compost and conditioning the soil. Bulbs get planted. Gutters get cleaned. Leaves get raked. Perennials get groomed. We might think of it as a time of slowing down after such a busy summer, but in many gardens, autumn is just as busy with seasonal chores.
Autumn is when many of the spring, and some of the early summer, blooming perennials get divided. That means that they get dug up, split into smaller parts, and then replanted. Because there will be more smaller plants after the process than there were bigger plants before the process, some should get planted over a larger area, in other parts of the landscape, or shared with friends.
Not all perennials need to be divided annually, and some may never need to be divided at all. Perennials that bloom in autumn or winter, such as Japanese anemone and bergenia, get divided in spring, since they will have plenty of time to recover from the process to bloom on schedule. Black-eyed Susan does not likely care if it gets crowded, but can get divided simply for propagation.
Lily-of-the-Nile should be divided if it gets too crowded to bloom well. Division allows more room for the individual shoots to grow and bloom as they should. However, because it takes a while for newly divided shoots to recover, they should only be divided every few years or so, and only if they happen to be getting crowded. African iris gets divided if overgrown plants are looking shabby.
It is not always necessary to dig entire plants. If dividing New Zealand flax just for propagation, it is easier to pry the desired number of side shoots from a mature clump, without digging the main part of the clump. Agave pups might be (very carefully) pried off of larger rosettes just to keep the main rosettes neat. Black-eyed Susan and other deciduous perennials get divided while bare.
Root pruning is nothing new. It is done more commonly than we think about for many aggressive perennials like lily-of-the-Nile, that like to disperse their roots into areas where we want to grow more docile annual bedding plants or vegetables. We might do it halfway, or more, around a shrubby plant during spring or summer if we plant on digging and moving it the following autumn. For most small and low profile plants, root pruning is sort of tolerable. The plants that we do it to may not like it, but it is sometimes necessary, and better than not doing so.


We may not get much foliar color in autumn here, but we get enough. Sweetgums do not need much cool weather to color well. They would probably have colored better and held their foliage a bit better if the weather got cooler faster, but we can not complain about what we got. Most of the crape myrtles are still completely green. Cottonwoods are defoliating, but without much color. Maples are rare here. The three best trees for color in autumn here are sweetgum, pistache and flowering pear. Of these, we happen to have several sweetgums here.








It may not bloom profusely, but cape honeysuckle, Tecoma capensis, blooms sporadically at random times throughout the year, and often while not much else is blooming. The bright reddish orange flowers contrast nicely against glossy evergreen foliage. Some blooms are slightly more reddish, while others are slightly more orangeish. A somewhat more compact cultivar blooms with light yellow flowers.
Junipers have a bad name. So do eucalypti. Too many of the wrong types were planted back at a time when they were too trendy. Those that were planted into inappropriate situations grew up to cause problems. The names of all junipers and eucalypti are now synonymous with those problems, even though there are many types of both genera that are quite practical for landscape purposes.
The same cooling weather that is initiating fall color is what finishes the zinnias that bloomed so colorfully through summer. Like tomatoes, they can stay out in the garden until they succumb frost if they continue to perform, and if the space they occupy is not needed for something else. There should be no guilt with replacing them sooner. After all, they are technically warm season annuals.
As zinnias, petunias, cosmos and other warm season annuals fade in the cooling weather, we might add a few chrysanthemums or marigolds for color through autumn, or we might go straight for pansies, violas or other cool season annuals that will provide color through winter. In the locally mild climate, there is always potential for some sort of colorful bloom. Mild weather has advantages.
By ‘big trees’, I don’t mean the various ficus trees that can grow up to the ceiling, and be quite happy inside. I am referring to the shade trees that live out in the yard, or forest trees that live beyond that. They are outside for a reason . . . or actually, several reasons. They are too big to bring inside. They probably would not like the climate inside. No one wants to rake fallen autumn leaves inside. Well, you get the point.