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The frosty temperatures have put an end to tender annuals, herbs, and most perennials. If you haven’t brought in your houseplants from their summer vacation, do it now.
Add 2 to 4 inches of shredded leaves, composted manure, or garden compost to perennial borders and garden beds once the ground has frozen completely.
Continue to feed the compost pile with grass clippings and dried plant material removed from garden beds. Avoid adding diseased plants to the pile. Turn the pile regularly to speed decomposition.
Before temperatures go below freezing, disconnect outside water sources, drain hoses, and store indoors. Sharpen and oil tools. Store all unused herbicides, pesticides, fertilizers, and chemicals in original, labeled containers. If cardboard containers have become wet, consider disposing of the product. Avoid storing chemicals in unmarked plastic or glass containers because it’s too easy to forget what they are. Check expiration dates on products to be sure they’re still viable.
Clean birdbaths, but try to maintain a water supply for birds over winter. Small heating coils can be used in stone birdbaths to prevent water from freezing.
Clean and refill bird feeders. Regularly cleaning and rinsing bird feeders is essential to prevent spread of disease.
All ceramic, cement, or terra cotta containers should be emptied, cleaned, and stored in a frost-free space. Soilless mix from containers can be stored in a pile outside and combined with equal parts fresh mix for next year’s containers.
In the event of snowfall, avoid using salt-based de-icing products in or around garden areas. Shovel snow before it freezes on sidewalks and sprinkle sand on walkways close to plantings.
Continue to plant deciduous trees and shrubs as weather permits. The alternate time for planting is next March, before plants leaf out. Apply 2 to 4 inches of wood chips, shredded bark, leaves, or compost to root zones of newly planted trees and shrubs. Be sure to pull mulch 4 inches away from tree trunks.
Continue to water trees and shrubs, especially evergreens, until the ground has frozen completely.
If rabbits, rodents, or deer have been a problem in past winters, take precautions with valuable woody plants now. To keep deer from rubbing antlers on tree trunks, spread garden netting or snow fencing around abused trees. Creation of physical barriers is more effective than sprays. Deter rabbits and rodents from overwintering in gardens by cutting down their winter habitats, such as ornamental grass clumps or perennials left standing for winter interest. Protect tree trunks from gnawing rabbits by setting up 12 to 16 inches of hardware cloth tacked into the soil 3 inches away from the trunk.
If necessary, construct burlap windbreaks 12 inches away from any newly planted, sensitive shrubs. The screens will buffer damaging effects of bitter, northwest winter winds.
Antidessicant sprays are not recommended for routine use on broadleafed evergreens. Some gardeners have used these products on rhododendron, azalea, boxwood, or holly to protect foliage from the drying effects of wind. Research indicates, however, that the waxy coating these products create can interfere with normal transpiration in the plants' foliage.
Protect hybrid tea, floribunda, multiflora, climbing, miniature, and newly planted roses late this month or when we have had several days of 20-degree weather. Mound 12 to 18 inches of lightweight peat moss or composted manure at base of roses. This mound will sink down over the winter. Prune hybrid tea rosebushes back to knee height. Other types of roses can be pruned as needed early next spring before growth begins. If desired, further protect plants by caging with chicken wire and stuffing leaves into cage; alternatively, punch quarter-sized holes in rose cones and place them over roses. Hold cones in place with bricks or other weights.
Continue to plant hardy spring-flowering bulbs early this month if weather and soil conditions permit. After planting, broadcast a 5-10-5 fertilizer over the soil surface and water well. If rabbits, rodents, or deer have been a problem in past, consider planting varieties of the following pest-resistant bulbs: ornamental onion, grape hyacinth, fritillary, narcissus, windflower, or winter aconite. Some gardeners recommend lining the planting hole with ½ inch of sharp sand or gravel before setting in bulbs. These products help deter rodents from digging.
Cut to the ground all remaining dried perennial material not intended for winter interest. Add to your compost pile.
Fertilize lawns for a final time early this month with a slow-release organic product high in nitrogen. Chicago area soils are naturally high in potassium and phosphorus, and most lawns don’t require more. This nitrogen application will help lawns retain green color longer in winter and color up faster in early spring.
Try to avoid walking on frozen turf; this breaks grass blades.
Plants brought indoors this fall might exhibit temporary “transplant shock” in their new environment due to changes in light and temperature. Sun-loving houseplants might suffer during cloudy winter season. If possible, consider supplemental artificial lights. Avoid overwatering houseplants. Cut back on fertilizer in general, except for plants intended to bloom all winter, such as miniature roses or geraniums.
Most houseplants appreciate a 10- to 15-degree difference in day and night temperature. Monitor plants for early signs of problems. When indoor heat is turned on, natural humidity disappears. Try to wash plants occasionally in a warm shower. Humidifiers and pebble trays can help raise humidity.
Pot up pretreated bulbs, such as amaryllis, paperwhite narcissus, and others, for holiday blooms.
Extra hardy bulbs not planted outside this month can be potted up and forced for indoor blooming. Plant bulbs in wide, shallow pots in a soilless mix. Large bulbs are planted side by side with just their tips showing. Little bulbs are planted with ½ inch of mix covering them. Water well and place pots in a refrigerator, cold frame, garage, or shed where the temperature remains between 35 and 40 degrees Fahrenheit. If storing in a refrigerator, cover pots with plastic wrap and avoid storing ripening fruit in same area. Some fruit releases ethylene gas, which inhibits flower formation. Major bulbs require 12 to 14 weeks of cold storage; little bulbs require a few weeks less. When pale yellow sprouts begin to show, pots can be brought out of cold storage into a bright but quite cool room (55 to 65 degrees F.) for about two weeks. As flower buds begin to develop, bring pots into a warmer room but avoid direct sunlight. Water as needed.