By November the garden and the gardener are usually ready for some down time. You might be tempted to skimp on clean-up chores or put them off until spring, but it's worth the effort to get it out of the way before winter rides in and takes the choice away.
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Pictured: In the midwest, try to select plants as smokebush (Cotinus spp.) the for winter cold hardiness and summer heat tolerance, bearing in mind that the heat of summer may be accompanied by drought conditions. Photo by Becke Davis for ILCA
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Fall clean-up in the yard and garden
Barring unseasonably warm weather, by November the last lawn mowing of the season has been completed.
Most of the leaves have fallen by now, but give your lawn and garden a once-over before they are covered with snow. It's easier to clean up leaves and garden debris while they are dry and loosely packed than when they are sodden and clumped with ice and snow. Leaving them is not a viable option unless you want to risk killing the grass under the leaves. Letting the debris overwinter is also an invitation to rodents, pests and plant diseases. While you should remove leaves and debris in your plant beds and lawn, it is not always necessary to cut the plants back at this time of year.
If you are not familiar with the growth habits of your shrubs and trees, hold back on the pruning until you find out if they bloom on old or new growth as you may be pruning away next year's blossoms. Some experts feel that marginally hardy plants, including some roses, may have a better chance of surviving the winter if pruning is delayed until early spring. Hold off on fertilizer, which encourages new growth and weakens the plant's ability to withstand cold weather extremes.
After a hard frost, it will be obvious which perennials need to be cut back and which can wait until spring—if they are sodden and wilted after a cold spell, cut them back now. If they still look good—as sedums, Russian sage and many grasses do—leave them for winter interest.
Apply mulch to plant beds for winter protection but remove it when temperatures warm up in the spring.
Before packing away the hose, your plants may benefit from additional watering if the weather is dry. Make sure that the water drains away from plants and trees. Few plants like to sit in water and poor drainage over the winter may cause the roots to rot.
Take this time to have your lawn mower cleaned and serviced so it will be ready to go with sharpened blades next spring
Winterizing containers and garden ornaments
Bring in containers of tender plants to overwinter indoors.
Empty and clean remaining containers and windowboxes thoroughly before storing them in your shed or garage. If tempted to leave them outside and reuse the soil next spring, don't be surprised to find a mess after mice or raccoons dig them up looking for tasty seeds or roots. While reusing the soil may seem cost effective, you may be exposing next year's plants and flowers to an assortment of pests, fungi and diseases.
Fragile pots as those made of terra cotta may crack or crumble if left outdoors over the winter. Bring those inside, along with any decorative items or garden art that might fade or crack.
Glass gazing globes are unlikely to survive the winter but metal globes ( which look almost the same ) can safely be left out. Metal windchimes won't break, but the strings holding them together may rot before the winter is over, and benches of wood and wrought iron may also be worse for wear by next spring.
Plant hardiness—not just an issue of zones
Even normally hardy plants are susceptible to sudden extremes of cold while they are actively growing, despite the fact that the same plants might be able to survive much colder temperatures later in winter when the plant is dormant.
In addition, some plants may be extremely hardy from the standpoint of roots or stems, but other parts of the plant can be susceptible to winter damage or dieback. Stems and leaf buds may survive a harsh winter, while less hardy flower buds may die.
In the Midwest select plants for winter cold hardiness and summer heat tolerance. The heat of summer may be accompanied by drought conditions. Plant survival in extremely cold winters is based in part on a plant's ability to harden against the cold, and also on the rate and degree of the plant to acclimatize to the cold and to reacclimate to the cold after unseasonably warm periods. Plant hardiness in subfreezing temperatures is based on both avoidance and tolerance of freezing.
Plants of marginal hardiness may still survive a year of temperature extremes if sited correctly. Microclimates, within every landscape, are small, localized areas that may offer protection from exposure to drying winds and hot sun.
Select plants that will survive
Regardless of their hardiness zone, plants are more likely to survive harsh conditions when they are planted in soils with the appropriate pH and site conditions ( sun, shade, levels of moisture, etc. ) that are best suited for the particular species. Professional landscape contractors can advise you as to the genus, species and cultivars that are most likely to survive our hot summers and cold winters.
Some plants proven successful in this area include serviceberries ( Amelanchier spp. ) , chokeberry ( Aronia spp. ) , peashrub ( Caragana spp. ) , white fringe tree ( Chionanthus spp. ) , summersweet ( Clethra alnifolia ) , smokebush ( Cotinus spp. ) , pearlbush ( Exochorda spp. ) , witch hazel ( Hamamelis spp. ) , juniper ( Juniperus spp. ) , crabapple ( Malus spp. and hybrids ) , tree peony ( Paeonia hybrids ) , ninebark ( Physocarpus opulifolius ) , sumac ( Rhus spp. ) , lilac ( Syringa spp. ) , yew ( Taxus spp. ) , Viburnum ( Viburnum spp. ) and Weigela ( Weigela florida ) .
For information about ILCA and member landscape contractors and garden centers call Monday through Friday 630-472-2851, write ILCA, 2625 Butterfield Road, Suite 204W, Oak Brook, IL 60523 or e-mail information@ilca.net for print material.
Copyright 2007, Illinois Landscape Contractors Association. Repinted by permission.
SOURCES:
Past ILCA Hints for November
Parts of this article have been adapted from 'Temperature Tolerance: The Highs and Lows of Hardiness' by Becke Davis, published in ILCA's The Landscape Contractor magazine, March 2006
'Plant Cold Hardiness,' by Harold Pellett and Robert Schutzki, Winter 2006, Vol. 17, No. 1, Landscape Plant News, Landscape Plant Development Center, Mound, MN
'Measuring Cold Hardiness in Woody Plants,' by Leena Linden, May 2002, Dept. of Applied Biology, Horticulture, University of Helsinki, Finland
'Cold Hardiness of Holly,' by Kenneth D. Cochran, Secrest Arboretum of the Ohio State University, Special Circular 189, Ornamental Plants: Annual Reports and Research Reviews, 2002, http://ohioline.osu.edu/sc189
Growing Shrubs and Small Trees in Cold Climates, by Nancy Rose, Don Selinger and John Whitman, 2001, Contemporary Books,
