Our temperate climate and generally mild winter allows us to plant practically year-round (we’re so lucky)! December is still a good time to plant deciduous trees and shrubs.
For Fresh Color
- Now that most leaves have dropped, we look forward to the stars of the winter garden: ‘Yuletide’ Camellias, Cyclamen, Coral Bark Japanese maples, colorful heaths, Wintergreen (berries), and Red Twig Dogwoods all show vibrant shades of red or crimson now and will look great in containers and flower beds for winter.
- Our year-round resident Anna’s Hummingbird loves to visit winter-blooming camellia blossoms for sips of nectar to stay warm and energized. If you prefer pink over red, ‘Pink-a-Boo’ is a cultivar of ‘Yuletide’ and blooms around the same time with lightly fragrant, perfectly pink flowers that are equally loved by hummers!
For the Lawn & Landscape
Keep an eye on weather and protect new plantings as necessary:
- Harvest Guard or floating row covers are easy to use and offer winter protection to tender plantings.
- Wind can also be damaging—use stakes to support plants, provide windbreaks, and/or apply MoistureLoc to help plants retain moisture and reduce evaporation during extreme weather.
Adequate watering:
- Make sure plants in greenhouses or cold frames, containers, and sheltered areas (under eaves) receive adequate water.
- Water new plantings and evergreens thoroughly before cold weather arrives.
- If heavy frost warnings or below freezing temperatures are in the forecast, water plants before it freezes—use a watering can or bucket if hoses are stored for the season.
Watch for drainage problems during heavy rains: Berms, bioswales, rain gardens, and French drains are great solutions for poor drainage. Call our landscaping department to arrange for services at 503.777.7777.
Turn compost piles and cover with a tarp to protect from heavy winter rains.
Keep up with sprouting weeds: Short spurts of weeding done during this time can greatly reduce your spring weed crop!
Scatter slug bait (Sluggo or Slug Magic) while you’re in the garden—slugs remain active during mild weather; you can significantly impact future population by controlling them now!
For the Edible Garden
- Do a soil test for pH and primary nutrient levels (use home test kit or consult Master Gardeners for a mail-in test).
- Spread wood ashes from the fireplace on vegetable gardens evenly and sparingly; use no more than 1.5 lbs per 100 square feet per year. Do not use ash if the soil pH is greater than 7.0 or potassium levels are excessive.
- Shelter bare patches of garden soil with a layer of mulch, compost, or shredded leaves to reduce erosion and compaction from rain.
In the Garden Shed
Keep a supply of frost blankets, burlap, or row covers for last-minute plant protection. Landscape staples, clothespins, or binder clips are useful to keep covers in place.
Basic Pruning List
Autumn (September to mid-December):
- Thin shrubs and trees only as needed (further pruning may result in new growth that won’t harden off before winter).
- Remove dead branches from trees and shrubs, as needed, and branches that are damaged or may cause damage from winter wind or snow and ice.
- Cut roses to waist/chest high to reduce winter damage.
For the Indoors
- For festive indoor color: Buy a poinsettia or Christmas cactus. Protect poinsettias from cold, provide plenty of light, and don’t let the leaves touch cold windows.
- Monitor houseplants for adequate water and drainage; watch for pests and other early signs of trouble (water and fertilizer requirements are generally less in winter). Plants may struggle with low humidity as indoor air becomes dryer from heater and fireplace usage. Increase humidity levels by misting plants frequently or by using a pebble tray.
- If you need to move a large indoor plant to accommodate the Christmas tree, be sure to keep the plant away from furnace/heater vents, cold windows, and drafts from frequently used doors.
Just for Fun
- Create festive outdoor arrangements for deck/patio: Fill empty flower pots and outdoor containers with soil (or use leftover soil); purchase fresh-cut branches of evergreens (noble fir, incense cedar, juniper, holly); add outdoor ribbon and lights to shine for the holidays!
- Feed the birds in the garden: Now is a great time to bird-watch from the kitchen window and admire tiny flocks of finches or bushtits feasting on the last seeds of fall. Keep feeders clean and refill regularly.
View the garden tips and checklist for January in the Garden. Or go back and view the tips and checklist for November in the Garden.