Dig In: Garden checklist for week of Dec. 18

The final days of fall will be chilly and foggy. According to the National Weather Service, Sacramento can expect “widespread frost and fog” Saturday through Monday. Ground moisture and frosty nights will combine to create thick fog in many sections of the greater Sacramento area.

Overnight lows will dip to freezing or just below; stay on frost alert the next three nights. Daytime highs will be on the cold side, too, topping out at 53.

Midweek cloud cover will keep nights warmer – above 40 degrees – and help warm afternoons, too. The final shopping – and gardening – days before Christmas (and first days of winter) should be in the high 50s, says the weather service.

Unfortunately, those clouds are unlikely to drop any local rain; check soil moisture, then turn on irrigation as needed.

* Wednesday is the first day of winter, the shortest day of the year – and the traditional time to plant garlic and onions for harvest in summer.

* Mulch, water and cover tender plants to protect them during threat of frost. Succulent plants are at particular risk if temperatures drop below freezing. Make sure to remove coverings during the day.

* Just because it rained last week doesn't mean every plant got watered. Give a drink to plants that the rain didn't reach, such as under eaves or under evergreen trees. Also, well-watered plants hold up better to frost than thirsty plants.

* Keep poinsettias in a sunny, warm location. Water thoroughly. After the holidays, feed your plants monthly so they'll bloom again next December.

* Prune non-flowering trees and shrubs while they're dormant.

* Start pruning roses even if they’re still blooming. Make sure to remove foliage and rake out fallen leaves from beneath bushes to prevent spread of fungal disease.

* Clean and sharpen garden tools before storing for the winter.

* Rake and remove dead leaves and stems from dormant perennials.

* Bare-root season is here. Plant bare-root berries, kiwifruit, grapes, artichokes, horseradish and rhubarb. Beware of soggy soil. It can rot bare-root plants.

* In the vegetable garden, plant fava beans, head or leaf lettuce, mustard, radicchio and radishes.

* Browse through seed catalogs and start making plans for spring and summer.