December is turning out to be a cold month this year, but nevertheless gardeners love to be outdoors. It’s a great time of year to do some of the heavy work in the garden as opposed to sweating it up in the heat of summer.
Leaves. Don’t put up the mower yet. Not all leaves have blown off the trees. Although turfgrasses have stopped growing, you can use the mower to chop up and recycle the leaves back into the lawn or collect them for mulch or a compost pile. The isles between rows in a garden are an ideal place to put excess leaves, creating an all-weather walkway and reducing soil compaction. By the end of next year, the leaves will have turned into rich compost.
Prepare gas-powered engines for winter. The owner’s manual is the best guide to winterizing a lawn mower, tiller, garden tractor or other powered equipment. The main steps generally include draining the fuel tank and the engine of fuel — or using a fuel stabilizing additive, which allows you to leave fuel in the tank over winter; draining and changing the oil; cleaning and sharpening, adjusting and lubricating the various parts as needed; and replacing or cleaning the air filter.
Drain and store garden hoses and watering equipment in a readily accessible location. Lawns and other plants may need an occasional watering during a prolonged dry spell.
Pruning: We get lots of questions about when it’s okay to prune trees, shrubs and roses. In general, once the weather gets and stays cold, pruning of deciduous plants (ones that lose their leaves) can be safely done. Rose experts advise waiting until mid-February to prune roses (except those that only bloom once in spring – prune those after they finish blooming).
Plants which bloom in early spring, like azaleas, forsythia and bridalwreath, should be pruned after they flower. Pruning of hydrangeas, which bloom later in spring, should also be delayed until after blooming. Most other plants that bloom in late spring and summer can be pruned during wintertime, because these types bloom on new growth produced in the new year.
Evergreen hedges can be sheared or cut back in the winter also, ideally just prior to the first flush of spring growth.
Once again I join the chorus of many other horticulturists in discouraging the severe topping of crape myrtles down to gnarly stubs. It ruins the overall form and beauty of the plant, and looks especially ugly in the winter time when no leaves are on the plant. It is not necessary to cut back crape myrtles, so don’t think you need to just because you see others doing so.
Planting: There’s still time to plant pansies, violas, stock, snapdragons, ornamental cabbage / kale and dianthus. These colorful annuals will live through the winter and be spectacular next spring. They work especially well when mixed with bulbs. Chose bright and light colors if you’d like the display to be easily seen from a distance.
Cold hardy trees and shrubs can be planted this month. Just take care to water them carefully, not letting them dry out, nor keeping the soil sopping wet.
If you are planning to create a new area for flowers, shrubs or vegetables, prepare the soil now while suitable conditions exist, even if you are not yet ready to plant. Prolonged winter and spring rains often delay planting if the soil is too wet to cultivate. Loosen the soil, remove grass and weeds, and work in well-rotted leaves, compost or other organic matter. If you discover that the soil stays wet longer than it should, create a raised bed to facilitate better drainage by adding more organic matter, expanded shale or sand, and soil.
Don’t forget any tulips and hyacinths you may have chilling in the refrigerator. After 45 to 60 days of chilling, they can be set out in the landscape. Plant them in clusters or groups for the best effect, rather than in a single row.
Wildlife: Remember to provide food and water for birds this winter. You can attract just as many birds with a bird bath as with food, especially during dry spells. If you put out a variety of seeds, like sunflower, thistle, safflower, and millet, plus suet, you will draw a diversity of birds. Once you begin putting out bird food, continue feeding them through the spring time.