Planting Trees and Shrubs -- Continue planting perennials, groundcovers, herbs, roses, and trees and shrubs. Also plant native wildflowers such as California poppies.
Dividing Perennials -- Now is a good time to divide perennials, especially those that bloom in the spring. This way, they'll have time to establish themselves before it's time to flower.
Smart Pruning -- Prune deciduous fruit trees. After pruning, spray with dormant oil to prevent fungal diseases and pest problems.