Oregon State University Extension Service

December Garden Calendar

Timely advice on garden chores, fertilizing, pest control, and more from OSU Extension.

These tips are not necessarily applicable to all areas of Oregon. For more information, contact your local Extension office (http://extension.oregonstate.edu/find-us).

Oregon State University Extension Service encourages sustainable gardening practices.

Practice preventive pest management rather than reactive pest control. Identify and monitor problems before acting, and opt for the least toxic approach. Conserve biological control agents such as predators and the parasitoids that feed on insect pests.

Maintenance and cleanup

  • Western Oregon: Do not walk on lawns (https://catalog.extension.oregonstate.edu/ec1521) until frost has melted.

  • Spread wood ashes (https://today.oregonstate.edu/news/sweep-wood-ash-fireplace-garden) evenly on your vegetable garden. Use no more than 1.5 pounds per 100 square feet per year. Don't use if the soil pH is greater than 7.0 or if potassium levels are excessive.

  • Protect new landscape plants from wind. Use stakes, guy wires or windbreaks as needed.

  • Yard sanitation (https://today.oregonstate.edu/news/take-one-more-go-garden-retiring-winter): rake leaves, cut and remove withered stalks of perennial flowers, mulch flowerbeds, and hoe or pull winter weeds.

  • Turn the compost pile and protect from heavy rains, if necessary.

  • During heavy rains, watch for drainage problems in the yard. Tilling, ditching, and French drains are possible short-term solutions. Consider rain gardens and bioswales as a longer-term solution.

  • Check stored flower bulbs, fresh vegetables, and fruits for rot and fungus problems. Discard any showing signs of rot.

  • Tie limbs of columnar evergreens to prevent snow or ice breakage.

  • Central/eastern Oregon: Water your plants every six to eight weeks with a deep soaking to keep them from drying out.

  • Western Oregon: Make sure that landscape plants in protected sites receive water regularly during the winter.

Planting and propagation

Pest monitoring and management

Use chemical controls only when necessary and only after thoroughly reading the pesticide label. First consider cultural, then physical and biological controls. Choose the least-toxic options, and use them judiciously. Some examples include insecticidal soaps, horticultural oils, botanical insecticides, and organic and synthetic pesticides.

Indoor gardening

  • Protect poinsettias from cold. Place them in sunlight; don't let the leaves touch cold windows. Fertilize with houseplant fertilizer to maintain leaf color.

  • Monitor houseplants for adequate water and fertilizer. Water and fertilizer requirements generally are less in winter.

Source URL: https://extension.oregonstate.edu/gardening/techniques/december-garden-calendar