WSU Extension Snohomish County Master Gardeners SCMG Education Outreach November/December GARDEN TIPS AND TASKS
November and December bring dark, short days with cold frosts, heavy rains, wind storms and occasional snowfall in Snohomish County. Below are some tips to help prepare for the changing season. We also hope you have utilized this publication for finding various ways to deal with problems that come up or questions you’ve had. If you have not, there is no better time than now to get started on the benefits of this webpage. SPOTLIGHTS IN THIS ISSUE PEST MONITORING AND MANAGEMENT - Cankers and lesions on tree bark, tent caterpillar egg masses on branches, spruce aphid damage, scales, rabbit and vole damage, slug control, home invader - western conifer seed bug. GENERAL OVERALL MAINTENANCE -Soil protection, monitoring winter moisture, end of season care of tools, irrigation systems, and garden beds. EDIBLES -Garden clean-up, mulching, seed catalogs, fruit tree/small fruit selection. FLOWERS AND FOLIAGE - Dahlia storage, leaf/wood chip mulch, forcing bulbs, propagating, protecting trees and shrubs from winter injury. LAWNS - Last mowing and fertilizing of the season. PLANT OF THE MONTH NOVEMBER - Hart’s tongue(Asplenium scolopendrium. PLANT OF THE MONTH DECEMBER - Springwood Pink winter heath (Erica carnea 'Springwood Pink’).
PEST MONITORING AND MANAGEMENT
Most foliage that is going to fall has left branches bare by November and December, so this is an ideal time to look closely at bark, branches, and twigs for problems or the potential for problems. Inspecting all your plants is a good idea, closely scrutinizing those plants that seemed stressed, grew very little, or looked wilted – these could be early indicators of a problem.
Good air circulation is important for general health; this is a good time to prune out inward growing or crossing branches.
Be sure to remove all diseased or infested plant material (this includes fruit) from the ground beneath your plants as they may harbor the beginnings of new problems.
Healthy debris is best left as “nature’s free compost material.”
Western conifer seed bugs are 3/4” long, and are harmless to people and plants. They prefer a warm winter home and may try to share yours! Hand pick, vacuum, or freeze. (When squashed they give off a foul odor.)
Michigan State University publication; Western conifer seed bug.
Thoroughlyreadthepesticidelabeltoensuresafehandling.Choosetheleast-toxicoptions andusethem judiciously.Instead of pesticides/herbicides, consider cultural changes as well as physical or biological controls.Use chemical controls only when necessary.
Clean your tools with steel wool, removing all rust and soil. Sharpen edges with a stone or file, then lubricate with a silicone or oil-based spray lubricant. Regular motor oil will work but will leave a residue which needs to be removed before use in the spring.
Sharpen the blades of your mower for next spring’s exuberant grass growth. Some stores will do blade sharpening, or you can buy tools that sharpen at the correct angle.
WSU publication; Garden Tool Care and Maintenance.
Next year’s catalogs are available by mail or on-line. Many seed catalogs 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 (such things as “days to maturity” and planting dates).
WSU Extension Publication; How to Read a Seed Catalog.
Late fall and winter is a great time to plan next year’s garden. Check your notes from this year and adjust your plans as necessary. Graph paper makes visualizing your garden plots and raised beds easy.
You may also be considering putting in fruit trees. Before you buy you may wish to consult these publications:
WSU Extension Publications; Why Backyard Fruit Trees are not for Everyone.
Maintenance/Clean-Up If you haven’t already, spread an inch or so of compost over your perennial beds and around shrubs, then top with 3-4 inches of mulch.
If you have older mulch on beds, add more to get about 3-4 inches.
Mulch will insulate roots from freezing, avoid frost heaving the plant out of the ground, and keep the pounding winter rains from compacting the soils.
GetChipDrop.com has free dumps of large quantities of wood chips. Other options are store-bought bags of mulch material, shredded leaves, conifer needles, fern fronds, etc., The best mulch is the one that does not compact into a mat that blocks water penetration.
Snohomish County Master Gardener Foundation publication; Tips and Tasks; October.
Shred larger leaves with a leaf shredder or mower. Put mulched leaves directly into beds or add them to your compost pile. You could stash a leaf pile in an out-of-the-way corner and allow it to compost.
Don’t use waxy leaves (e.g. rhododendron, magnolia) or diseased material.
Most plants have started to die back or are in full “give-up” mode:
Hostas and others like them will have turned to mush. Cut them to the ground.
Mark those locations so you won’t plant on top of them when you see that “open space”.
Dahlias can be cut down once the frost blasts the leaves. In warmer locations, you can overwinter tubers in the ground, protecting them from rain with fern fronds, evergreen boughs, etc. Excess rain may cause rot. If you prefer to dig up the tubers, now is the time.
Dahlia tuber storing: remove the stems and layer in slightly moist newspapers, sawdust, perlite, etc. The trick is to keep the air around the tubers moist but the tubers themselves not wet. Check every month and adjust the moisture if you see any evidence of rot.
Label the dahlia tubers by name and/or color before storing. You can write on the tuber itself.
See: Snohomish County Master Gardener Website publications; Tips and Tasks; October.
Herbaceous perennials like hardy geraniums that have withered can be cut close to the ground. But those with sturdy stems, such as phlox, helianthus, and Joe-eye weed, can be cut to 12-18 inches to provide shelter and nesting sites for pollinators.
Rose pruning happens next spring, but do shorten long stems to about 3 feet to avoid breakage in a wind or under snow load. This does not apply to climbing and rambling roses!
Mound the rose base with 6-8 inches of mulch and remove all leaves from both the shrub and the ground around the trees. This helps reduce black spot in the spring.
WSU Extension Publications; Growing Roses in Washington State: A Seasonal Calendar.
Tying limbs of upright evergreens together with twine may prevent breakage. Arborvitae especially have a tendency to split open their pyramid shape when snows lean on them!
If trees have tender young bark, consider shielding them from weather.
Desiccating winds and frost can harm or kill young or sensitive trees. Place stakes near the tree at the windward side and attach burlap or frost cloth around the stakes, making a shield that doesn’t touch the trunk. You could also wrap the trunk, but with caution. Read:
WSU Extension publication; Environmental Injury: Frost Cracks, Home Garden Series
Rains have probably lessened any need to water, but if a freeze is forecast, check your soil under trees and shrubs and water well if that soil is dry. They cannot take up water once the soil is frozen.
Except for dead or diseased limbs, hold off pruning trees and shrubs until they enter dormancy. When finally dormant, prune correctly, consulting:
Washington State University Spokane County Extension publication; Keys to Good Pruning.
If we get snow, consider pushing the clean snow beneath trees and shrubs to help insulate the ground. Also, after a heavy snow, gently shake the excess from the branches that look likely to break or bend.
WSU Extension Publications; Environmental Injury: Cold Temperature Injury of Landscape Woody Ornamentals (Home Garden Series)
If the ground has not yet frozen, there is still time to plant the last of those spring blooming bulbs; they won’t do much for you sitting on the shelf in your garage! (If the ground has frozen, you may want to try to “force” the bulbs in an indoor pot, enjoy, and then add to your spring garden.)
Lawns may have stopped growing in November. If yours is still growing, make your last mowing at a lower height than usual. This will allow the grass to photosynthesize but not get matted and have rot issues if it snows.
Walk on the grass as little as possible. Read the tip about soil compression damage above in General Maintenance.
PLANT OF THE MONTH - NOVEMBER Asplenium scolopendrium Common name: Hart’s tongue (uh-SPLEE-nee-um sko-lo-PEN-dree-um) For winter interest, evergreen ferns offer a wide variety of foliage and textures. Hart’s tongue is deer- and rabbit-resistant (as long as the critters don’t get too hungry), drought-tolerant once established, and grows well in various soil types, though it grows best in well-draining, organic-rich soil, in light to deep shade. Rarely bothered by insects or diseases, even slugs avoid ferns! Mulch the root areas if freezing temperatures are predicted soon after planting. The roots are rhizomes so they divide easily. You can stump your friends with this evergreen, broadleaf fern. Hardy in zones 5-9, Hart’s tongue sends up fronds up to 18” long and 3” wide and shine in the sun. Mature size is about 18” tall by 18” wide. A Great Plant Pick.
‘Fern Growers Manual’ by Barbara Joe Hoshizaki and Robbin C. Moran, from Timber Press
Photo Credit; Dianne Elledge; WSU Snohomish County Master Gardener
PLANT OF THE MONTH - DECEMBER Springwood Pink winter heath Erica carnea 'Springwood Pink’ (ER-i-ka KAR-nee-a)
This beautiful groundcover from the Ericaceae family is slow growing and known for its pink blossoms in mid winter.
This plant has a compact habit and grows to 1 foot high and 2 feet wide.
The one third inch leaves are arranged in whorls around the stems.
Small flowers are cylindrical, blooming in mid to late winter.
Winter heath prefers acidic soils and winter sun. These traits make it a good companion to azaleas and rhododendrons.
Plant either in late September through late November, or March through May.
The foliage should almost touch the soil surface when planting.
Space plants appropriately to allow for growth.
Water in the spring and during dry spells, especially in the first year after planting.
Shearing this plant after flowering will keep it dense.
Propagate either through tip cuttings or layering (a process of bending a low growing, flexible stem to the ground. Anchor and cover a portion of the stem with soil. This allows the stem to grow roots.)
The Springwood Pink winter heath is low maintenance and deer resistant.