WSU Extension Snohomish County Master Gardeners SCMG Education Outreach November GARDEN TIPS AND TASKS
SPOTLIGHTS IN THIS ISSUE PEST MONITORING AND MANAGEMENT - Spruce aphids, oystershell scale, lecanium scale. GENERAL OVERALL MAINTENANCE - Soil compaction, preparation of tools and watering systems for winter. EDIBLES - Garden clean-up, mulching, freeze protection, pruning raspberries. FLOWERS AND FOLIAGE - Mulching; winterizing beds, roses, and dahlias; planting/forcing of spring-blooming bulbs; sheet mulching to create planting beds. LAWNS - Mowing, final fertilizing, avoiding soil compaction. PLANT OF THE MONTH - Skimmia japonica, Japanese skimmia.
PEST MONITORING AND MANAGEMENT
Most foliage that is going to fall has left branches bare by November, so this is an ideal time to look closely at bark, branches, and twigs for problems or the potential for problems. Inspect all your plants. Closely scrutinize those plants that seemed stressed, grew very little, or looked wilted during the growing season– these could be early indicators of a problem.
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.”
Washington State University (WSU) Extension publication; Bugs and Blights.
Watch for …. yellow blotches on spruce needles or yellowed or brown needle drop.
Spruce aphids, which emerge from late fall to March, may be present. Start looking for damage now, but you may not see these tiny green insects (1/16 inch) until February when they increase in numbers.
Sticky liquid may also be seen on the plant. This is called honeydew, the liquid excrement of aphids.
Photo credit: Lecanium scale crawler in winter: Sharon J. Collman; WSU Professor Emeritus.
Keep in mind…
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: firstname.lastname@example.org
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:
Thoroughly read pesticide labels to ensure safe handling. Choose the least toxic options and use them judiciously. Instead of pesticides/herbicides, consider cultural changes as well as physical or biological controls. Use chemical controls only when necessary.
The label must state that the pesticide is for the problem you are addressing.
Soil compaction…difficult to repair, easy to prevent. Fall and winter rains, repeated foot traffic, or machine use all contribute to compacted soil. It will affect plant growth and may cause runoff of nutrients, chemicals, and topsoil. What to do…
Try not to walk on garden beds and lawns, especially if there are frequent rains.
Root growth continues in the winter and does best in loose soil.
Compressed soil is difficult for soil microbes, worms, and insects to move through and cycle nutrients.
Soil compaction removes air pockets that store water for non-rainy winter days.
Designate pathways to reach specific areas of your lawn or garden.
WSU publication; A Home Gardeners Guide to Soils and Fertilizers.
Be sure to monitor your plants in greenhouses and cold frames. The added humidity in these enclosed spaces can encourage fungal diseases, and the warmth and shelter may increase insect populations.
Regularly inspect your plants under eaves or in sheltered locations. Water if too dry.
It’s not just temperature that affects plant growth; day length counts, too. The Persephone Period, named after the daughter of Demeter in Greek mythology, is the time we receive less than ten hours of daylight a day. For Snohomish County, the Persephone Period lasts roughly from Halloween to Valentine’s Day. Find the exact day length for any day:
United States Navy Observatory website; Astronomical Applications Department.
Remove all dead or diseased canes and clean up all debris around the plants.
Cut out thin, short, or crossing canes if you need to maintain a smaller size (in containers or raised beds).
Summer bearing raspberries: Remove any dying floricanes at the crown to prevent disease spores from overwintering and spreading to new canes. (Floricanes are the second year canes. They have three leaflets per leaf plus shorter spaces between leaves on the cane. Primocanes have five leaflets and longer internodes).
Bundle the remaining primocanes and tie them to the supports.
Everbearing raspberries: Cut all dead floricanes to the crown. For the primocanes, remove the dead tips, cutting a few nodes below the dead portion.
Oregon State University Extension publication; Growing Raspberries in Your Home Garden.
Dahlias can be cut down and, in many areas, protected from the rains with fern fronds or evergreen boughs. If you prefer to dig up the tubers, now is the time.
To store dahlia tubers, remove the stems and layer in sawdust, shavings, perlite, etc., surrounded by moist newspapers. Do not pack in potting soil. The trick is to keep the air around the tubers moist but the tubers themselves dry, but not desiccated. Check every month and adjust the moisture; remove tubers that show any evidence of rot.
Label the dahlia tubers by name, or at least by size and color.
Hold off pruning trees and shrubs until they enter dormancy during the colder winter months. Fresh cuts are less likely to be infested by insects and disease. Dead or diseased material may be pruned out at any time.
Michigan State University Extension publication; Winter dormancy and chilling in woody plants.
Bulbs can still be planted if the ground has not yet frozen. 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, then add to your spring garden.)
Walk on the grass as little as possible. Read the tip about soil compression damage above in General Overall Maintenance.
PLANT OF THE MONTH - November Japanese Skimmia Skimmia Japonica (SKIM- ee- uh juh-PON-ih kuh) Japanese skimmia is a slow-growing, low maintenance, shade-loving evergreen shrub. It is dense and mounding, with leathery dark green leaves, which have a spicy scent when crushed.
Native to Taiwan and Japan, it grows 3-5 feet tall and up to 5 feet wide in zones 4-9.
Plant skimmia in acidic or neutral pH, well-drained soil. It prefers part to full shade or sun-dappled areas.
Fragrant, creamy white flowers appear in spring with male flowers having a stronger scent.
If a male plant nearby, female plants can produce red berries in the fall, which attract birds and are showy throughout the winter.
This slow-growing plant is deer resistant.
All parts of the plants are poisonous if ingested in large quantities.
Skimmia is a fine specimen or hedge plant and works well in mass plantings.
Prune after spring flowering to reduce size, but pruning will remove potential berries.
In warm, dry weather it can attract spider mites.
Washington State University (WSU) Clark County Extension publication; PNW Plants; Japanese Skimmia.