WSU Extension Snohomish County Master Gardeners SCMG Education Outreach December GARDEN TIPS AND TASKS
SPOTLIGHTS IN THIS ISSUE PEST MONITORING AND MANAGEMENT - Cankers, tent caterpillars, slug eggs. GENERAL OVERALL MAINTENANCE - Monitor moisture in protected areas, gift ideas, Winter Speaker Series. EDIBLES - Planning for next year’s garden: vegetable seed-starting, choosing fruit trees and small fruits. FLOWERS AND FOLIAGE - Winter injury protection, pruning, winter garden design, holiday indoor plants, propagation by cuttings. LAWNS - Final mowing if needed, rake leaves or mulch-mow, avoid walking on lawn. PLANT OF THE MONTH - Mahonia cultivars, Oregon grape.
PEST MONITORING AND MANAGEMENT
Bare branches afford you the opportunity to look for problems that might have been hidden by foliage. Watch for…dead patches or sunken cracked areas on the bark of plants.
These may be cankers, dead sections of bark on a tree or shrub. They may have started as lesions caused by an injury to the plant, allowing a bacterial or fungal pathogen to enter. Canker diseases frequently weaken and can even kill plants.
What to do…
Provide proper culture to increase plant vigor and help in recovery.
Avoid bark wounds.
Prune off branches with cankers, cutting several inches back from the canker.
Wait for a dry day.
Sanitize tools between cuts.
Monitor the tree next spring.
Washington State University (WSU) website Hortsense; Maple: Nectria canker.
Accurately identify the pest or problem. For help you can contact the Master Gardener hotline at 425-357-6010 or send an e-mail with a photo to: email@example.com
The Snohomish County WSU Master Gardener Office Clinic is open from 11:00 AM to 3:00 PM Monday through Thursday. Walk-ins are welcome! The clinic is located in the Administration Building at Willis D. Tucker Park, 6705 Puget Park Drive, Snohomish, WA 98296.
If you want to do the research on your own, here’s a helpful website:
Gardening books make great gifts and are available for both beginning and experienced gardeners.
Buy tickets online for individual talks or a season pass to the Winter Speaker Series.
Presented annually by the Snohomish County Master Gardener Foundation, the Winter Speaker Series begins in January. Professional and university-trained experts cover a broad range of topics with emphasis on gardening in the Pacific Northwest. See the schedule:
Check your protective coverings (for example, burlap, cold frame and tunnel covers) to ensure the wind hasn’t displaced them.
Next year’s seed catalogs are available by mail or on-line. Many are very informative and can help you decide what to plant next year. When ordering from a seed catalog, consider our climate and location. Seed companies from other areas may include information that is not accurate for our area.
Washington State University (WSU) Extension publication; How to Read a Seed Catalog.
If you’re looking for gifts for friends, family—or yourself—a flowering plant just might be the answer. Nurseries are well stocked now with a variety of colorful plants just in time for the holidays. For ideas on particular plants to buy and how to care for them:
Oregon State University (OSU) Extension Service publication; Colorful indoor plants make delightful gifts for the holidays.
PLANT OF THE MONTH - DECEMBER Oregon grape Mahonia cultivars Mahonia x media 'Charity', Mahonia x media' Winter Sun' (Ma-HONE-ee-ah) New family name: Berberidaceae Mid-winter, natural food for the hummingbirds? A splash of bright, sunny color and fragrance for the gardener? Yes, please! Mahonias will bloom in darkest winter, feeding the overwintering Anna’s hummingbirds.
Mahonias are slow-growing, evergreen shrubs.
Many Mahonias have dramatic whorls of spiny leaves that are very similar to holly plants.
An exception to sharply toothed leaves is ‘Soft Caress’ which has bamboo-like whorls of barely toothed leaves.
The pollinator- and hummingbird-adored, golden bloom clusters appear in fall to winter.
These nectar-rich plants provide an important food source in winter for hummingbirds which must feed frequently.
In late summer to autumn, the grape-like blue-black berries feed many bird species.
They thrive in full sun to dappled shade (deep shade makes a leggy plant), and in any soils, except soggy soil.
Mahonias do not like to be moved, so site them with that consideration.
They are winter hardy in zones 7-9.
Mulch to protect the roots. Protect from freezing winds that may “burn” leaf tips.
Prune to thin out crowded branches, or trim the tips to make a bushier plant in spring.
If Mahonias are not happy with the conditions, they are susceptible to diseases such as rust or powdery mildew.
Mahonia aquifolium is native to our region. There are several cultivars praised for less leggy growth, more stunning blossoms, fragrance, and disease resistance.
Mahonia x media ‘Charity’ rises to 15 feet and blooms in fragrant, slender clusters over an extended winter period.
Mahonia x media ‘WInter Sun’ is shorter at 4-10 feet and is said to have the best fragrance. Hummingbird- enticing flower sprays are held at the very tops of branches.
Mahonia repens, also a native, is a creeping ground cover that has tight clusters of yellow flowers rather than upright sprays. The leaves may turn purple in winter.