December Gardening Tips

Garden Maintenance

• Continue to rake up leaves for composting and to control pests and diseases.
• Clean up garden beds.
• Keep an eye on the weather report, protect frost-tender plants when the temperature falls below 32 degrees.
• Prune non-flowering trees and shrubs while dormant.
• Clean up debris around fruit trees to prevent disease.
• Mulch, water, and cover tender plants to protect from frost.  Be sure to remove coverings during the day.
• The birds stay in Northern California through the winter.  Since flowers are scarce in most gardens now, it’s important to keep your feeder filled; clean and refill it every few days.

Fertilize

• Apply chelated iron to azaleas, gardenias and camellias if leaves are yellowing between the veins.
• Feed annuals with a complete fertilizer once a month or fish emulsion every two weeks.

Spray: Check the California Backyard Orchard website for current information.

• To smother overwintering insect eggs and pest such as aphids and mites, and scale, spray deciduous flowering and fruit trees as well as roses with dormant oil after the leaves have fallen.

What to Plant in December

Trees, shrubs, perennials

• Choose and plant camellias and azaleas.
• Bare-root roses start appearing in nurseries this month.  Shop while selections are good.
• Choose a living Christmas tree; keep it outside until Christmas week.  Dig a hole now to plant after the holidays.

Flowers

• Brighten the Holidays with poinsettias, amaryllis, calendulas, Iceland poppies, pansies, Christmas cactus, and primroses.
• Keep poinsettias in a sunny, warm location: feed monthly, water thoroughly.
• Continue to plant tulips, narcissus, daffodil, and hyacinths for a longer show of blooms in the spring.
• Take advantage of end-of-the-year bulb sales; plant at once.
• Prune for Holiday Greens.  Holly, juniper, pittosporum, podocarpus, pyracantha, and toyon all benefit from a winter grooming.  Use the cuttings for holiday decorations.

Vegetables

• Late this month nurseries begin selling bare-root artichokes, asparagus, berries, grapes, kiwifruit, horseradish, and rhubarb.  Buy and plant early in the month while roots are still fresh.  If the soil is too wet to plant, temporarily cover the roots with moistened mulch to keep them from drying out.
• Plant seeds for cabbage and spring lettuce in a cold frame or in the greenhouse.

Lawns

• Turn off your automatic sprinklers once the winter rains get started.

Cover Crops

• Even small gardens will benefit from the use of cover crops, or “green manures”.  Tilling, weeding, harvesting and foot traffic in most home gardens tends to destroy soil structure.  Planting cover crops such as grasses or legumes is an easy way to revitalize the soil.