Southern California Coastal & Inland Valleys
Give one last deep watering to grapevines and deciduous trees to make them more cold-hardy. Feed all overwintering plants with a no-nitrogen, high-phosphorus, high-potassium fertilizer to help them with winter hardiness.
Move Mulch Back to Tree Dripline
Rake mulch from under trees back to the drip line. The bare soil can then more easily absorb the day's heat and release it to the trees at night. This technique also discourages overwintering of disease-carrying bacteria and insects
Fertilize cool-season grass lawns. Lower the blade height on your lawn mower to encourage short, bushy growth.
Seed New Lawns
You can still seed new lawns or reseed thin spots in established ones. For good germination, water newly seeded lawns two or three times a day for the first two weeks. For another two weeks, water once a day. Then, change to watering only three times a week but for longer periods. You want the moisture to reach 2 to 3 inches down so the roots grow deeply into the well-prepared seedbed. When the grass gets bushy and about 3 inches tall -- about a month after sowing -- the lawn is ready for its first mowing. Allow the soil to become firm and fairly dry before mowing, however, to avoid compressing the new lawn with mower wheels and your footsteps.
Check Plants for Snails and Slugs
Regrettably, the cool, moist weather brings back snails and slugs, just in time to attack succulent seedlings. Hand pick and squash them after dark and after overhead watering. A friend of mine pays neighborhood kids a penny apiece for the critters.