Adding plants to the garden in November
by Mary Robson, WSU Area Extension Agent
November, for all its gray skies and often uncomfortable temperatures, presents great planting opportunities for maritime Northwest gardens. Getting out and digging is a good way to cope with the soggy mood doldrums from dark days. (Don't dig or plant if the ground's frozen or saturated with rain.)
November, often the most rainy month of the year in this area, gives gardeners a good chance to evaluate the way soil in gardens drains. Dig a hole about a foot deep. Fill it with water. The water should drain out at about an inch an hour. If the drainage is so poor that the hole takes two or three days to drain, many plants won't thrive in that location.
During winter, gardeners in this part of the Northwest lose more plants to wet soil conditions than to freezing. Roots require air for good health and survival. Saturated soils doesn't allow oxygen to reach the root, and the plant succumbs to drowning. Correct the drainage by installing drainpipes if necessary. Plants may have to be installed on a berm, or raised area, to provide better drainage.
Soil amendments can help to improve growing conditions on clay soils; digging in organic material such as composted leaves, homemade compost, or purchased products such as GroCo, Tagro, or Cedar Compost can help. Spread a layer about 3 inches deep on the top of the soil and dig it down about 8 inches. Don't add sand to clay--that makes concrete! And ignore advice to add gypsum, which has no effect on clay soils. And remember that soil amendments alone won't correct poor drainage. Often professional help is needed to evaluate the situation and design improvements.
If you plan to add soil amendments, work them into an entire planting bed rather than into the hole for a tree or shrub. Research has shown that trees and shrubs grow better if they have no radical differences between the soil in the planting hole and the surrounding soil. Roots will move out into the soil more readily if it's uniform. Planting in "native soil" and then mulching over the top is a recommended practice for installing trees and shrubs. Or, as is suggested, working amendments into a large planting area so that the soil is homogenous.
Selecting plants is far more enjoyable than preparing the planting area, but the best-adapted plants won't thrive in heavy clay or poorly drained soils.
In November, trees, shrubs, and perennials can be planted. Selecting shrubs for winter bloom and fragrance gives gardens an enticing winter aspect. We are fortunate in the maritime Pacific Northwest to have dozens of plants that will bloom or supply leaf interests in January and February.
For winter color, look for red-twig dogwood, Cornus alba (Tartarian dogwood). A selection of this which grows somewhat shorter is Cornus alba "Siberica." These plants are cut to the ground yearly in spring, to allow for a new crop of brilliant red branches that show brightly after leaf-fall.
From late fall on into winter, Viburnum tinus, which is an evergreen viburnum, carries pink and white-budded bunches of flowers. Admire them at a distance--some observers react to the smell as to that of a wet dog. The plant's a valuable and beautiful hedging plant. Another viburnum, Viburnum x bodnantense "Dawn," flowers sporadically throughout winter, opening bunches of pinkish blooms on mild days. "Dawn" drops its leaves and presents bloom on rather gawky stems. What makes it extraordinary is the fragrance of the plant, a clear sweetness that lasts well when a bloom is picked for indoors.
A shrub that combines beautiful leaves and a memorable fragrance, but gets to have an awkward name, is Sarcococca. These plants have shiny, clean foliage and elegant form, growing in very deep shade. Look for S. humilis, low growing (to about 1 1/2 feet). This one spreads by runners underground, gradually filling larger and larger spaces. S. ruscifolia can reach 4-5 feet, and is one of the tidiest and most appealing shrubs for year-round gardens. These plants bloom with tiny, unobtrusive white flowers that resemble a handful of fringe. But the fragrance, like honey, drifts around gardens in winter, often as early as January if the weather is mild.
Check nurseries for early-blooming Camellia sasanqua, with open flowers in white, red, or coral, with bunches of yellow stamens in the center of the flowers. Several fine cultivars of this are "Yuletide" with small red flowers, and "Apple Blossom" in pink and white.
Be sure to get spring-blooming bulbs planted. They need 12-13 weeks of chill time in the ground in order to bloom well in late February, March, and April.
Putting spring-blooming bulbs in containers is a fine project for late November. Crocus, daffodils, hyacinths, and tulips do well planted in containers for spring bloom. Choose a container that drains well. Use a frost-proof container such as a wood or plastic. Fill the container 2/3 of the way with a well-drained potting soil. Place bulbs close together, only 1/2 inch or 1 inch apart. Cover the bulbs with another layer of soil and water in well. The bulbs will be close to the top of the pot, so close that their tips or "noses" are nearly poking out of the soil. After watering them in well, put the pot in a cool place for the required 12-13 weeks of chill.
The simplest way to provide the chill period is to bury the pot in garden soil, adding a mulch over the top to prevent freezing. Or group pots together on the ground and pack a mulch such as compost or leaves around them. Check under the mulch in January to see if shoots are emerging. If they are, remove some of the mulch to allow light to the shoots. Also patrol for slugs wintering over under the mulch and preparing to attack emerging shoots.
After the required 12-13 week chill period, it's possible to bring the pots into light and warmth for early bloom. A cool, light area helps the flowers develop properly and stay sturdy. It's sometimes difficult to provide the cool temperatures needed: spring bulbs grow best at temperatures between 50 and 65 degrees. If they get too warm inside the house, they will get long stems and become droopy.
It's also possible to leave the containers outdoors and let them bloom in the normal spring sequence, with the added pleasure of placing the potted bulbs on display beside doorways and on patios.
Visit WSU's Agriculture Site on the World-Wide Web at http://www.cahe.wsu.edu.