Preparing Plants for Winter
Weather extremes and wildlife damage are two main concerns facing
landscape plantings during the winter season. While we are at the
mercy of winter weather, there are some things that can be done
to help prevent serious damage to perennial plants, trees, shrubs,
Winter mulches should be applied to protect perennial plantings
from winter weather. These are suggested to help protect perennial
flower plantings and strawberry beds from alternating freezing and
thawing cycles over the winter, not from freezing. Its best
to wait awhile before mulching perennials and strawberries until
about Thanksgiving or later so plants have gone dormant and the
soil freezes to apply the mulches. Straw or evergreen boughs make
good winter mulches.
For most perennial flowers, allowing the dead plant material to
remain until spring may help protect the crown of the plant, although
if the bed is mulched later this fall it doesn't really matter.
Most ornamental grasses provide interesting winter foliage effects
when left standing.
Protecting Plants from Gnawing Damage
Rabbits and voles (field mice) are the primary animals that may
gnaw on tender bark of trees and shrubs in winter. Putting up a
barrier, such as poultrywire or hardware cloth, is the best defense.
Put a fence around shrubs, and secure with a few stakes. Put a loose
cylinder of hardware cloth around the trunk base of younger trees
susceptible to vole or rabbit gnawing. Removing excess vegetation
and debris near plants will also help reduce cover, especially for
Repellents are also available to help protect plants from gnawing
animals. Research studies have concluded results vary depending
on location and even the specific year when using repellents. However,
there are some important points to consider. Keep in mind repellents
will reduce but not eliminate animal damage to plants. A good chickenwire
barrier may eliminate rabbit damage to shrubs, but a good repellent
may simply reduce the damage. So if some damage occurs, don't blame
the manufacturer, as damage may have been reduced but not eliminated.
Remember results vary considerably in studies.
There are two types of repellents, contact and area. Contact repellents
are applied directly to plants and repel by unpleasant taste for
the animal. Some product examples include DeerAway, Ro-Pel, Miller
Hot Sauce, and thiram (a fungicide). Area repellents are applied
in the vicinity of plants and usually repel by smell. Examples include
Hinder, dried blood, bar soap, and human hair.
Research studies show not every repellent works in every situation,
but contact repellents are more effective than area repellents.
Commercial products appear more effective than "home-made"
remedies. If you're planning to use a repellent this winter to protect
shrubs and trees, read the labels thoroughly. Most need to be reapplied
during the winter. Consider fencing or other barriers for more dependable
protection - even though the initial costs are higher, remember
they can be reused.
Preventing Winter Desiccation
Another problem facing evergreens during winter is desiccation,
or drying out, from the wind and some cases sun. It's important
that evergreens have adequate moisture in the soil right up until
freezing. Monitor conditions throughout the fall to assure evergreens
have adequate moisture available. Shrubs in very exposed sites may
benefit from additional protection. Options include loosely wrapping
with burlap, putting up a snowfence or other type of windbreak,
or using commercially available antitranspirants, which are wax-like
materials sprayed on plants late in the fall to help prevent drying
out. These work especially well on broadleaf evergreens.
Last winter was a very tough one for lawns. Snow mold (a fungus)
and vole damage were both very high. Voles will make runways under
the snow in lawns as they feed on grass blades and roots and are
protected from predators. Help prevent damage from occurring by
continuing to mow lawns until grass is completely dormant in fall.
Mow lawns at a final height of about 2 inches. Also clean up any
excessive vegetation near lawns, as this provides cover for voles.
Both gray (Typhula blight) and pink snow mold (Fusarium patch) may
occur in northern Illinois. During the wet, cold weather of early
spring, snow mold may be highly visible as matted, crusty looking
areas. As conditions dry out, snow mold will gradually fade but
infected areas may remain as weak or even dead turf. Conditions
favorable for snow mold include excessive use of fast-release (water
soluble) nitrogen fertilizer in early to mid fall, excessive thatch,
shade, poor drainage, and excessive debris (such as leaves or straw)
on the lawn. Areas receiving drifting snow or piles of deposited
snow are also prone to snow mold.
There are ways to avoid snow mold from becoming a severe problem.
Follow sound fertilization programs, using fertilizers containing
slow-release or controlled-release nitrogen. Adequate levels of
phosphorus (P) and potassium (K) should be available in the soil.
Manage thatch via aerification, or removal from vertical mowing
(dethatching). Improve air circulation by pruning or removing dense
vegetation bordering problem lawn areas. Mow lawns until completely
dormant in fall. Fungicides are available but rarely suggested for
October - November 2001: Preparing
Plants for Winter | Heating with Wood Needs
Care and Consideration | Amaryllis for
Winter Beauty | Understanding Fall Color