Gardening Guru: Gardening Tips for December
By Peyton Ellas
UCCE Master Gardener
An important use for the garden in December is as a place to escape the hustle and bustle, crowds, over-heated houses, and a revved-up pace. During and after leaf-fall, we can glimpse the structure or “bones” of our garden through our deciduous trees and shrubs. Stroll a garden path, or sit with a hot beverage among the colors of fall and winter. The native garden comes alive with sharpened blue-greens, greys and silvers, yellows, and every shade of brown. If you don’t think brown can be beautiful, challenge yourself to visit a California garden, let nature be part of your holiday spirit, and discover the beauty of stillness and the world in waiting.
Another important use is as a supply source for decorations. If you have a pine, spruce, cedar or redwood tree in your yard, you probably have discovered that home-grown fresh-cut greens are excellent tied in bunches with a pretty bow or gathered into a traditional wreath. Holly, fir, cedar, juniper, mistletoe, redwood, magnolia, pines and Podocarpus foliage are traditional choices, but don’t be afraid to use toyon, coffeeberry, rosemary, bay, eucalyptus, native sage, live oak and even manzanita. You can add nuts, pomegranates, acorns, pinecones, buckeyes, and any other natural objects. Reminder: only use LED candles and other non-flame lights around any greenery indoors, as many evergreens can still look fresh but be quite dry as the month goes on.
Garden chores: Watch for frost warnings and protect your sensitive plants. Move potted plants under the eaves, patio or other protected areas. Plants will survive better if kept moist but not overwatered. Throw away any mummies left on fruit trees.
We are finishing up our annual cutting back and tidying up as winter approaches. Shrubs and perennials that benefit from severe pruning (cut back almost to the ground) include non-compact Buddleia (butterfly bush), Lion’s Tail, Matilija Poppy, Mexican Sage, most penstemon, Jerusalem sage, Rudbeckia, Epilobium (Zauschneria), and yarrow (Achillea). For the rest, just remove any branches and old flower stalks that look dead or bedraggled. You can adopt a cut and drop approach in the natural garden to encourage healthy populations of soil microorganisms. In the formal garden or where stone mulch is used, add the cuttings to the compost or green-waste bins. If you get too busy to cut everything back, don’t worry; you can wait and prune in spring when the new growth appears. To encourage woody shrubs like lavender, Ceanothus and santolina to be longer-lived, trim them back lightly several times a year, including once in early winter.
If your garden has a natural look, leaves can sometimes be left in the beds if they don’t prevent rain from reaching the soil. If there are too many, or if the appearance of all those leaves bothers you, add them to the compost or mulch pile. If there is an insect or disease problem, fallen leaves and fruit tree mummies (old fruit) should be put in the green waste bin or otherwise removed from the garden. Many insects overwinter in leaves and mulch, but not all of them are pests, so don’t over-react unless you know you have a severe pest problem.
Cold weather crops, such as broccoli, Brussels sprouts, cabbage and cauliflower grow well during the winter, and can be harvested as long as they are producing.
Critter control: After the leaves fall, spray fruit trees and roses with a dormant oil spray to kill any overwintering aphids, mites, scale, and whitefly.
Handpick slugs and snails or set out iron phosphate as a bait. To help control them, eliminate their hiding places under debris such as wood or pots. Unfortunately, many common garden plants, such as day lily and agapanthus, also make good hiding places. You can go on a patrol, or engage the help of children in the family and make it into a treasure hunt.
See any white moths around your winter veggies? That cute little dear is laying eggs on your prize broccoli or cabbage. The eggs will hatch into the cabbage looper and eat holes in the leaves. You can’t do much about the moth, but seeing one is the signal to start looking under the leaves for the next several days to snag the small, green caterpillars before they do much damage. Large plants can survive some damage, however, seedlings can be devoured. You can also spray with BT (Bacillus Thuringieis), sometimes marketed as caterpillar killer. Be sure to spray plant leaves thoroughly on the tops and bottoms.
Many other pests are dormant during winter, but during warm spells watch for earwigs in your greens and handpick or trap them under newspaper and boards.
What to plant: It is nearing the end of the bulb planting season, so nurseries may have them on sale. Choose healthy firm bulbs and make sure they are not mushy or moldy. Tulip and hyacinth bulbs should be cooled in the refrigerator (away from fruit) for six to eight weeks before planting, so skip those until next year. But you can probably get a decent bloom from daffodils, narcissus and hyacinth.
Asian greens and lettuce can be planted through the month, especially if you use cold frames, hoops, or row cover cloth.
You can also continue to plant frost-hardy trees, shrubs and perennials until at least mid-month. For the rest of December and through winter, turn your attention to designing and planning your spring improvements. Why not take a break from festivities to enjoy the December garden, or to hold a winter party out of doors? Happy Holidays!
You can find the Master Gardeners every Saturday from 8 a.m. to noon at the Farmer’s Market in the Visalia Sears’ parking lot on Mooney Boulevard.
To contact the Tulare/Kings Master Gardener Program, call 559-684-3325, e-mail firstname.lastname@example.org or write to 4437 S. Laspina St., Suite B, Tulare, CA 93247.
– This column is not a news article but the opinion of the writer and does not reflect the views of The Foothills Sun-Gazette newspaper.