Northern California Coastal & Inland Valleys
Shorter days and cooler temperatures mean that plants don't need as much water as they did during the active growing period. Container plants should be checked prior to watering to make sure the soil is not soggy. Use the finger method to see if the soil is dry to one knuckle depth before watering. Automatic irrigation systems should be reset.
Fall Garden Sanitation
Good housekeeping in the garden now means less problems with insects, diseases, and weeds next year. Keep fallen fruit and vegetables picked up off the ground. Clean up spent annuals and vegetables and compost them. Rake under shrubs to remove slug and snail hiding places, removing mulch from slug-prone plants and areas.
Pick and store herbs in the morning while their flavor is at its peak. Wait until the morning dew has dried from the leaves before picking. Dry harvested herbs in a dark, dry area such as on top of the water heater to preserve color and flavor. You can also freeze single layers of herbs on cookie sheets in the freezer. Remove them from the trays once frozen, store them in airtight bags or plastic containers, and return them to the freezer.
Water Redwood Trees
Keep watering redwoods until winter rains begin. Redwood trees need additional moisture now because the summer fog is gone for the year and our winter rains haven't started yet. Provide water directly to the roots by using soaker hoses. Cover the hoses with a layer of mulch to protect them from the sun.
Start a Compost Pile
Fall is the ideal time to start a compost pile. Fallen leaves, grass clippings, and chopped yard debris can be used to create "gardener's black gold." Simply cut up the larger pieces and throw everything into a pile. Mix the brown organic matter and green organic matter thoroughly, wet it occasionally with the hose, and turn the pile over from time to time with a spading fork. That's all there is to it.