December Garden Almanac
December is the month when Sonoma Valley gardeners can legitimately rest – at last the growing season is over and early spring doesn’t start again until…yes, next month. But relax in December!
That said, December is the month to begin the dormant spraying of leafless fruit and ornamental trees and shrubs. Dormant sprays destroy overwintering insects and diseases. You want to get started this month and get three sprayings in before bud break next March.
The past few years, we have gotten our first frost in the Valley in December. Have poly floating row covers handy to cover citrus and other tender plants. Don’t wait until the day before frost is predicted – that’s when the garden and hardware stores will be sold out of plant covers.
Here is a garden and nature roundup for December:
Annuals: Turn off irrigation systems and drain lines of standing water before the first freeze. Take an inventory of seed packets; check for expiration dates. Start planning the spring garden.
Perennials: Spread aged compost in your perennial beds. Lavender can be headed back this month in preparation for growth in spring.
Bulbs: Plant out crocus, hyacinth, and Dutch tulips that have been refrigerated for the last eight weeks. Set pansies, violas, and Iceland poppies above spring blooming bulbs. Cyclamen can be planted in the garden this month after you enjoy the blooms indoors for a few weeks.
Roses: Shop for bareroot roses this month while the selection is best. Bareroots can be planted any time before they start to leaf out in spring. Soak the roots of bareroots in a bucket of water before planting to plump them up.
Shrubs: After rains, add soil to low spots in the garden. Use aged compost as a mulch; spread it around the base of plants and across planting beds. Keep camellias and rhododendrons watered. If they go dry, the buds will go brown and drop later and you will have no blooms next spring.
Trees: Both conifers and deciduous fruit and flowering trees are available bareroot and balled-and-burlapped now. Prices for these trees will be less than container-grown stock. Choose trees that will fit height, width and water requirements in your garden or property at maturity. Some research now will save on regrets later.
Vegetables and Herbs: Start seeds of broccoli, cauliflower, cabbage, and Brussels sprouts indoors four to eight weeks before you set them into the garden. These will go into the garden in late winter so that they come to harvest before warm temperatures come in spring. Have floating row covers ready to protect crops from freezes.
Fruits and berries: Bareroot fruit trees and berries are in garden centers now. Semi-dwarf and dwarf varieties are best suited for home gardens. Check to see if the varieties you are looking for are self-pollinating or need a pollinator.
Garden Maintenance: Clean the garden of any spent plants and debris. Add aged manure to planting beds where you intend to plant next spring. Turn off irrigation water and outdoor faucets in advance of freezes.
Native Plants: Look for the pink-white bells of common Manzanita in bloom now, and also the brilliant red blooms of fuchsia-flowered gooseberry. Goldfields and buttercups are among the native perennials blooming this month. Look for the large red clusters of Toyon berries now.
Nature Alerts: From Sonoma County to Monterey County, monarch butterflies will be roosting; along the Sonoma coast monarchs visit the Sonoma Coast State Beaches just north of Bodega Bay. The National Audubon Society’s Christmas Bird Count comes in the last two weeks of this month and you can help count. This is a good month to take in ferns under redwoods along Sonoma Valley streams.
Kenwood Weather Averages: Temperature: Average High 59°F, Average Low 39°F, Mean 49°F; Average Precipitation 6.19 inches; Record High 83°F (1967), Record Low 15°F (1932).
Sunrise and Sunset: Sunrise on the 1st 7:09 a.m., Sunset on the 1st 4:50 p.m.; Sunrise on the 31st 7:28 a.m., Sunset on the 31st 5 p.m.
Moon: Last quarter/waning on Dec. 3; New on Dec. 11; First quarter/waxing on Dec. 18; Full on Dec. 25.
– Compiled by Steve Albert
Steve Albert is the author of The Kitchen Garden Grower’s Guide available at Amazon.com. He teaches in the landscape design program at the U.C. Berkeley Extension. He lives in Oakmont.