December Gardening Tasks
Expand the categories below to learn more about what you need to do this month.
Now is the time to test the soil in your planned beds for plant nutrients. UGA soil tests usually take 7-10 working days, so test now to have the results when you plant bulbs and beds. It is important to till in the lime needed (if any) for faster soil pH adjustment. You may also sample your vegetable garden or lawn.
The winter is a great time for growing things like mustard greens, turnips and turnip greens, collards, cabbage, broccoli, spinach, beets and such. Pine needles, straw mulch, floating row covers, and small garden hoop covers, can all be used to extend the growing season to at least the end of December.
Be sure to inspect your fruit trees. Remove any mummified remaining fruits, and rake up and dispose of old leaves and branches that may harbor diseases over the winter.
Now that temperatures are lower, use dormant oil sprays to control scale insects on fruit trees and shrubs.
Pick up fallen leaves, limbs, and other debris from lawns to prevent suffocation of the turf during winter. Store any leftover lawn fertilizers in a dry location and out of reach of children and pets. Seal the bags to keep moisture out! Store pesticides and fungicides in a cool (not freezing), dry location for winter, out of reach of children and pets.
Mulch perennial beds with 2 to 4 inches of straw, shredded leaves, or other lightweight material. Empty decorative ceramic pots and containers and store in a storage shed, garage or carport for winter. If unusually cold weather is predicted, mulch and protect ornamental cabbage, kale, pansies, snapdragons and other cool-season outdoor plants.
If you haven’t done it, make sure you plant those spring-flowering bulbs you purchased earlier in the fall, such as daffodils, tulips, hyacinths, and crocus. Enjoy the winter color from plants like pansies, snapdragons, ornamental cabbage and kale, hellebores, camellias, and such.
If houseplants are outdoors and are actively growing, you can fertilize foliage plants like ferns at 1 tsp. of a water-soluble fertilizer like 20-20-20 or 24-8-16/gallon of water once every 1-2 weeks. Water to leach out of the container. If the plant is a flowering plant in a pot such as impatiens, coleus or petunias/million bells, use 1 tsp. of a water-soluble fertilizer like 20-20-20 or 24-8-16/gallon of water once every 1 week. Water to leach out of the container. If the plant is a succulent such as jade plant, use ½ tsp/gallon of a high nitrate fertilizer like 20-10-20 once a month.
If houseplants are indoors and in subdued lighting, fertilize once a month with a water-soluble fertilizer (1 tsp./gallon/month).
To keep holiday plants looking good longer, keep them away from dry, drafty locations. Do not place near heat vents, doorways or drafty windows. Increase humidity around plants by placing them on a tray lined with pebbles, shallowly filled with water. Make sure the water does not enter the drainage holes. Winter is a challenging time for most houseplants because of the lower natural light and susceptibility to over watering. Be careful not to over-water houseplants. Growing media should be allowed to nearly or completely dry out between watering (but plants should never wilt). Unless your indoor plants are growing under optimum, high light conditions and are actually growing, do not fertilize them during the winter months.
Inspect indoor plants regularly for pests, especially ants, spider mites, aphids, white flies, scale insects and mealy bugs. Keep in mind that plant-specific temperature, light, and humidity are key to ensuring that indoor plants thrive.
Amaryllis is a popular plant for the holiday season. They can be forced to bloom now or planted outdoors for spring blooms.
One of the most popular indoor holiday plants is poinsettia. With proper care, this colorful plant will give weeks of color. Call the Hall County Extension Service for advice on after-holiday care for poinsettias.
If flower or vegetable plants did not perform as desired this year or new plantings are being planned, a soil test may be a good idea.
Now is a good time to pour through the seed and plant catalogs and online seed sources for new varieties. Make sure what you buy will thrive in our hot and humid zone 7b-8a climate! To be certain you can get what you want, make early seed orders now.