Most California native plants require minimal pruning and are best cleaned up in the cooler fall months.  After all, plants need their leaves to produce energy and thus growth, so it makes sense to prune only when they are in a dormant phase.

Trees, vines  and shrubs that you wish to shape are best pruned when young, say in the first 3 years, so that they grow in the desired shape, rather than cutting large branches later.

You will also find that winter deciduous plants are easier to visualize and shape in winter when they are leafless. So this is a good time to get rid of any cross branching or weak limbs.

Evergreens are best pruned soon after the flowers are finished. However, remember that allowing some fruit and seeds to develop will provide food for birds and other wildlife, so for habitat value prune lightly or skip alternate shrubs to allow some fruit to develop. Ceanothus and Arctostaphylos are species that are best pruned in spring after flowering.

Speed versus quality. Sages seem to be constant victims of the geometric shearing approach! But other plants are also vandalized in this way. Most native plant gardeners do not want their shrubs pruned into geometric shapes (balls and squares!) but convincing gardening staff to do otherwise can be challenging! If this is the case encourage a double pruning method. This method combines speed (keeping your gardening staff happy!) with a more natural finish (keeping you happy!) For this method allow the gardener to shear quickly in a rough ball shape, cutting about 1/3rd height of the plant, and then use pruners to randomly cut alternate branches lower. This will provide a more natural appearance as the shrub regrows.

Do deadhead flowering plants. This will encourage more and longer flowering. But again, remember that wildlife will appreciate you leaving a few flowers to produce seeds for them to feast on.

California fuchsia and Matillija Poppy appreciate a good military haircut. Apart from those you are saving for seed, cut back after the flowers are completely over. They will spring back full and green the next season. I cut my Fuchsia right down to the ground in winter, and the Matillija's to about 4". The Matillija's are ready for cutting back in June, although I always leave mine longer so I can collect the seed!

Other things to remember. Try to avoid pruning in heavily moist weather. This will help prevent infection. Disease risk can also be reduced by making sure the prunings are cleaned up, not left on the ground. This is also a fire safety issue, as pruned cuttings will dry out and ignite easily.

Finally, make sure your pruners are sharp. Clean the blades between each plant you are pruning to avoid cross contamination of any disease that may be lurking. Clean the blades and handles before you put your tools away.  Yes, I did say 'Put your tools away' - a novel concept in some households that will remain nameless!