Dig In: Garden checklist for week of Jan. 19

Cold mornings and sunny afternoons; that’s our current weather pattern and it’s expected to stay that way for another week.

With that combination comes frost danger as well as patchy morning fog – as long as there’s still some moisture in the soil. We’re drying out fast.

According to the National Weather Service, Sacramento will dip to 35 degrees or lower almost every night this week, although no sub-32 nights are forecast (yet). The greatest threat of frost comes in the wee hours Wednesday.

Take frost precautions before you go to bed, including protection of sensitive plants. Don’t forget to water; moist soil can raise temperatures a few crucial degrees.

Check your soil moisture, too; with the lack of rain, you may need to irrigate, especially new transplants. No rain is in our forecast for at least another week.

Otherwise, our daytime temperatures will continue to be slightly above normal with afternoons hovering around 61 or 62 degrees – above average for mid-January in Sacramento.

Dress warmly in layers – and get to work:

* Apply horticultural oil to fruit trees to control scale, mites and aphids. Oils need 24 hours of dry weather after application to be effective.

* This is also the time to spray a copper-based oil to peach and nectarine trees to fight leaf curl. The safest effective fungicides available for backyard trees are copper soap -- aka copper octanoate -- or copper ammonium, a fixed copper fungicide. Apply either of these copper products with 1% horticultural oil to increase effectiveness.

* Prune, prune, prune. Now is the time to cut back most deciduous trees and shrubs. The exceptions are spring-flowering shrubs such as lilacs.

* Now is the time to prune fruit trees. Clean up leaves and debris around the trees to prevent the spread of disease. The exceptions are apricot and cherry trees, which are susceptible to a fungus that causes dieback if pruned now. Save those until summer.

* Prune roses, even if they’re still trying to bloom. Strip off any remaining leaves, so the bush will be able to put out new growth in early spring.

* Clean up leaves and debris around your newly pruned roses and shrubs. Put down fresh mulch or bark to keep roots cozy.

* When forced bulbs sprout, move them to a cool, bright window. Give them a quarter turn each day so the stems will grow straight.

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

* Divide daylilies, Shasta daisies and other perennials.

* Cut back and divide chrysanthemums.

* Plant bare-root roses, trees and shrubs.

* Transplant pansies, violas, calendulas, English daisies, snapdragons and fairy primroses.

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

* Plant bare-root asparagus and root divisions of rhubarb.

* In the bulb department, plant callas, anemones, ranunculus and gladioli for bloom from late spring into summer.

* Plant blooming azaleas, camellias and rhododendrons. If you’re shopping for these beautiful landscape plants, you can now find them in full flower at local nurseries.