December Gardening Guidelines
by Keith C. Hansen, Extension Horticulturist, Smith Co. – Tyler, Texas
December is the month when shorter daylight hours and cold weather really begin to restrict the gardener’s outdoor activities. Winter gives you a great opportunity to catch up on reading your favorite gardening magazines and books. Here are a few tips and topics to occupy the gardener’s time this month.
There’s still time to plant pansies. 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 bed to be seen from a distance.
Also, hardy trees and shrubs can be planted this month. Just take care to water them carefully, not letting them dry out, nor keeping the the soil sopping wet.
If you are planning to create a new shrub, flower or rose bed for next spring, go ahead and prepare the soil now. Dig it up, remove the weeds, and work in leaves and compost. If you discover that the soil stays wet longer than it should, add more organic matter, sand and soil and create a raised bed to facilitate better drainage.
Remember those tulips and hyacinths you have chilling in the refrigerator? After 45 to 60 days of chilling, they can be set out in the landscape.
Don’t get too anxious to do major pruning. Most woody trees and shrubs can be safely pruned December through early March. But, if you can’t justify the removal of each branch or limb, put up your clippers and go spade the garden instead.
Some of the right reasons for pruning include removing dead or winter-killed or diseased or insect-injured wood, as well as branches broken by wind or wild kids. Avoid severe pruning if possible. Never leave stubs, long or short, which do not heal properly and invite the entry of insects and disease.
Plants which bloom in early spring, like azaleas, forsythia and spirea, should be pruned after they flower, while those that bloom later in the spring and summer can be pruned during wintertime. Roses are pruned in mid-February except spring-only bloomers which are cut back after spring flowering.
One pruning practice that needs to be changed is how crapemyrtles are pruned. Every winter crape myrtles are severely cut back to short stubs resulting in ugly plants. Although there is disagreement among landscapers on whether or not to prune back crapemyrtles, scientific research indicates that early winter pruning of crapemyrtles can result in significant freeze damage.
In my opinion, it is better to leave crapemyrtles unpruned altogether. If you just cannot tolerate those seed capsules (which add winter interest to the landscape), then delay pruning until late February or early March, and remove no larger than pencil-sized twigs. Resist the urge to cut them back hard.
If it continues to be dry this month, occasionally water the lawn, shrubs and small trees to help prevent winter damage.
Winter is a good time to browse plant catalogs, visit nurseries and study your landscape to make improvements or additions. If you are not a do-it-yourselfer, get professional advice on landscape design. An attractive landscape around the house not only beautifies but also adds to the value of the property – an increase anywhere between 5 to 15 percent of the sales price.
Don’t let fallen leaves remain on the lawn all winter. Either mow them back into the lawn, collect them to be used as a weed suppressing and water conserving mulch, or compost them for use next spring and summer to improve the soil. Leaves left on the lawn can cause disease problems if a thick layer keeps the grass too wet and dark.
What does the vegetable patch look like now? Remove dead vegetation and weeds to prevent a build up of diseases, weeds and insects. Order seeds now for spring vegetables so you will have them in plenty of time for starting early transplants or sowing directly into the garden in early spring.
Most fall-planted vegetables if you haven’t experienced a really hard freeze yet. Many cool season, fall crops, like lettuce and spinach, have shallow root systems. So, be sure to frequently apply water to keep the soil slightly moist to keep the plants healthy and growing. Between the rows and around the plants in the garden is a good place to use leaves to help conserve soil moisture and control weeds.
Order seeds now for spring vegetables and flowers so you will have them in plenty of time to start early transplants or sow them in early spring.
Goldfinches, tufted titmouse, black-capped chickadees, and other birds will be showing up at feeders. Remember to provide both food and fresh 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.