Winter is here. Put your garden to bed for winter and prepare your garden for the dropping temperatures and wet season. Here are tips from the University of California Cooperative Extension Master Gardeners.

General Tasks

Compost: Turn compost and keep it as moist as a wrung-out sponge. Cover compost during the rainy weather to prevent it from becoming waterlogged.
Drainage: Correct any problems in low or poorly drained areas in the landscape.
Frost: Watch for frost warnings and protect sensitive plants. Light frost 32-29 degrees F, medium frost 28-25 degrees F, heavy frost 24 degrees F and below for four-plus hours.
Irrigation: Reduce irrigation or turn it off completely if rainfall is adequate.
Maintenance: Inventory all sprays and pesticides; take outdated or unneeded chemicals to a hazardous waste center.
Mulch: Add mulch to garden beds where bulbs are planted, and to areas where weeds have been removed.
Soil: Prevent compaction and poor aeration of soil by avoiding working, walking on, or using heavy equipment on wet soil.
Tools: Clean and sharpen dull blades, lubricate garden tools and repair damaged grips. Cleaning can be done with soapy water and a wire brush or steel wool; air dry and apply a light coat of oil to prevent corrosion. Tools with wood handles can be sanded and rubbed down with linseed oil. File cutting tools, including shovel blades, to sharpen. Store tools in a dry, covered area. Have your lawn mower serviced to get a jump on spring tasks.
Weeds: Inspect lawn and manage rainy season weeds before they flower, using nonchemical methods such as cultivation, hand weeding, or mowing; use toxic chemicals as a last resort. Destroy all roots and underground parts.

Edibles

Clean-up: Control over wintering pests by removing fruit mummies and fallen leaves on the ground from fruit and nut
trees, especially if codling moth has been a problem. Dispose in green recycle bin. Composting this material could reintroduce pests/pathogens to your garden.
Feed Plants: Fertilize citrus trees in January/February just prior to bloom.
Plan: Plan your summer garden and order seeds early.
Plant: Bare root deciduous trees, shrubs and vines, for example cane berries, fruits and nuts, grapes, and perennial vegetables. For planting, care and maintenance tips see: 
    Berries and Vines - https://cagardenweb.ucanr.edu/Berries/ 
    Fruit Trees - https://homeorchard.ucanr.edu/Fruits_&_Nuts/ 
Propagate: During the cool season, winter, and spring vegetables should be started indoors 6-8 weeks before planting out (in December and early January). Some can be direct sown. Warm season summer vegetables should be started indoors 8-10 weeks before setting out (late Jan-Feb). Optimum soil temperature for transplanting is 55-60°F.
Protect: Watch for frost warnings. If a frost is predicted, protect citrus, sub-tropical and tender plants. Pull the mulch away from trees and water well, keeping the root zone moist but not soggy. If not already done in November, cover trees sensitive to frost.
Prune: If not done in November, prune deciduous fruit and nut trees, such as apple, pear, and stone fruits. Prune grapes and cane berries now; it's too late once they have leafed out. Note: apricot and cherry trees are the exception;
prune these in July and August only.

Landscape

Clean-up: Do a general clean-up of the landscape on a dry day; avoid walking on wet soils.
Plan: Select blooming azaleas, camellias and rhododendrons while you can see their color. Order summer blooming bulbs to plant out in early spring.
Plant: Plant container ornamental trees, plants and shrubs except subtropical plants. These include frost tolerant
perennials; hardy spring blooming annuals; summer blooming bulbs; bare root deciduous trees, shrubs and vines (like roses); seedlings of cedar, fir, pine and spruce. Scatter wildflower seed if this was not done in November. Plant azaleas,
camellias and rhododendrons.
Propagate: Start frost tender perennials and warm season annuals. 
Protect: If a frost is predicted, water your plants, keeping the root zone moist but not soggy. Cover frost-tender species
as appropriate (bougainvillea, hibiscus and succulents).
Prune: Prune winter flowering shrubs just after bloom; woody shrubs and evergreen trees; hardy deciduous trees;
dormant shade trees; summer blooming vines; hydrangeas and summer-blooming perennials. Roses should be pruned
by mid-February. Wait to prune spring flowering trees and shrubs until after they bloom.