What to do in your Northwest garden in December
Many new catalog issues come out around Christmas; to get the best selection of plants, order early.
Give a present that lasts for years instead of weeks ― an azalea, Christmas cactus, kalanchoe, moth orchid (Phalaenopsis), or a tabletop Christmas tree.
If you're planning to add a conifer to your garden, consider buying one now and using it as a live Christmas tree before planting it in the ground. Some attractive garden-scale options include alpine fir (Abies lasiocarpa), Austrian black pine (Pinus nigra), and Korean fir (Abies koreana). Keep indoors only one to two weeks and water regularly.
Winter camellias (mostly sasanquas and hiemalis) are in flower now in Sunset climate zones 4-9, 17. 'Yuletide' (red flowers and yellow centers) is among the most beautiful and reliable. For something unusual, try 'Baby Bear' dwarf camellia. Plants are very slow-growing, reaching about 3 feet in five years.
Propagate evergreens. Start new camellia, daphne, mahonia, rhododendron, or rosemary plants from your existing shrubs. Peel a fingernail-size patch of bark from the bottom of a low-hanging branch, dust the wound with rooting hormone (available at garden centers), and press down until it touches the soil; secure it with a brick. The branch will root where it contacts the ground. After it's well rooted in a year or so, cut the branch free from the mother plant and transplant to another part of the garden.
Plant hardy tree and shrub varieties anytime. Water them well after planting and top them with a mulch of well-composted manure.
Care for houseplants. Lightly fertilize winter-flowering or winter-fruiting types (amaryllis, azaleas, Christmas and Thanksgiving cactus, hydrangeas, kalanchoes, mums, ornamental peppers, and poinsettias), but wait until spring growth begins before feeding foliage plants.
Prune for swags and boughs. Using sharp shears, cut winter greens, making each cut just beyond a side branch (don't leave stubs). Keep the plant's finished shape in mind as you work.
Chill paperwhites. When displayed in cool air (below 60° or so), the stems of these flowering bulbs do a good job supporting their blooms. But when you bring potted plants inside to enjoy their fragrance, the stems start flopping over. To prevent this, move the plants to a chilly porch or other cool, frost-free location whenever you leave the house for a few hours and before going to bed.
Treat paperwhite narcissus and ornamental peppers as living bouquets; when these beauties start to fall apart, just toss them out. Transplant hydrangeas and mums into the garden after the holidays. Azaleas, Christmas cactus, kalanchoes, and orchids can live and bloom in containers for years if you provide bright light, frost protection, and regular applications of fertilizer (azaleas do best if placed outdoors in summer).
Sand icy walkways. Unlike salt, sand doesn't hurt plants when it washes onto their roots, so it's a good choice for concrete and asphalt paths and driveways. But don't use on tiles or wood decks, since it may scratch them; use a de-icing chemical instead (available at home improvement centers).