What Happens to Your Lawn During the Winter Months?

What Happens to Your Lawn During the Winter Months?

What Happens to Your Lawn During the Winter Months? 

PART 8 – VOLE DAMAGE

Damage from voles can be a very unpleasant site in the spring when you see your lawn for the first time in months after the snow melts.  To make matters worse, vole damage seems to appear that much more dramatic when it’s combined with all the other conditions affecting the lawn that go along with winter including snow mold disease and winter kill.

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Vole Damage Tunnel

  Voles are small rodents very similar in size and appearance to mice.  They are herbaceous and tend to be prevalent in areas situated in close proximity to areas with suitable cover including wooded areas, parklands, bushes and shrubs, and tall grasses.

Vole

Vole

Vole damage is commonly most prominent during winters with long continuous periods of snow coverage.  The snow provides the voles with a sense of protection from natural predators as they can move about freely under the snow cover without exposure to the outside.

 

Voles tunnel along the surface of the lawn protected by the snow and create turf damage by feeding on the grass plants tissue and also from continuous “wear” from the traffic of tunnelling back and forth across the lawn.  Voles do not feed on the roots or crown of the grass plant and therefore the damage they cause is usually not considered severe.

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Vole Damage to a Lawn

Recovery can often take place on its own when damage is minor by simply lightly raking up the areas of matted down turf.  When damage is more severe and the tunnelling has been extensive, a more aggressive approach including overseeding, topdressing, and slitseeding may be required to repair the damage.

voletunnels

Vole Tunnel Closeup

What Happens to Your Lawn During the Winter Months?

What Happens to Your Lawn During the Winter Months?

What Happens to Your Lawn During the Winter Months?

PART 7 – SNOW MOLD DISEASE

Snow mold is a fungal turfgrass disease that commonly affects lawns in early spring.   The Symptoms and visual damage are very evident as the snow melts away and brown matted down circular patches of turf ranging in size from a few inches in diameter to over one foot cover the lawn.   Depending on the severity of disease activity, these patches coalesce together and form bigger patches when the conditions are favourable for the disease.

Snow Mold Damage

Snow Mold Damage

There are two types of snow mold disease that affect turf.  Pink snow mold also commonly referred to as Fusarium Patch, and Gray snow mold also known as Typhula Blight.   Pink snow mold poses a greater risk for more severe damage and can be identified with the distinctive pink coloured mycelium.  Damage to the roots, crowns and leaf may cause plant death and require renovation to bring back the lawn in these areas.  Unlike pink snow mold, gray snow mold mycelium is greyish white in appearance and requires snow cover for infection to occur.  Damage is usually only minor on the leaf blades and the turf can generally recover on its own from this damage.

Spring Snow Mold Damage

Spring Snow Mold Damage

Most of the turf species that make up a home lawn including Kentucky Bluegrass, Fine Fescue and Perennial Ryegrass are all susceptible to snow mold.   Although preventing snow mold disease can be tough, a few things to consider before going into winter to better prepare the lawn include:

  • Proper Fertilization (avoid applying excessive nitrogen)
  • Mow the lawn at the recommended height until it stops growing
  • Rake up leaves, clippings and other debris before snow cover
  • Core aerate and remove undesirable thatch accumulation

Although the appearance of the lawn with snow mold can look rather rough, this typically only lasts for a couple weeks until the lawn wakes up from dormancy and begins greening up and growing quickly.  As the lawn begins to dry up, lightly hand raking away the brown matted down areas can also help speed the recovery process up.   If more severe snow mold damage has taken place beyond just cosmetic, aggressive renovation practices may be required to repair these areas.  Cultural practices such as Core Aeration, Overseeding, Topdressing and Slitseeding can help with this.

What Happens to Your Lawn During the Winter Months?

What Happens to Your Lawn During the Winter Months?

What Happens to Your Lawn During the Winter Months?

PART 6 – LOW TEMPERATURE KILL

Extreme cold temperature conditions persisting for days, weeks and even months are nothing but normal to many parts of Canada during the winter months.  The winter of 2014 has proven to be this just this, with an exclamation point at the end of extreme cold temperatures lasting for months!  When the mercury dips below freezing the turfgrass plant is exposed to many extremes that can cause damage.  These freezing conditions cause damage, and Direct Low Temperature Kill is what this is known as.

The turfgrass plant in large part is comprised of water and when freezing temperatures occur, the water freezes forming ice crystals inside the turfgrass plant ultimately causing the damage.  Direct low temperature kill is most commonly a result when rapid drops in temperature occur, or when extreme cold temperatures persist.  Several factors can affect direct low temperature kill including:  the susceptibility of the turfgrass species, plant hardiness, rapidness of freezing, the number of times the plant freezes, and the rate of thawing.

lowtemperaturekill

Extreme Low Temperatures

Although there is no exact direct low temperature kill measurement or way to determine if, when, and how bad the damage could be, plant hardiness as it relates to turfgrass species tells us more about which species are more susceptible.  Creeping Bentgrass, and Kentucky Bluegrass are regarded as having very good plant hardiness whereas perennial ryegrass and fine fescue have poor plant hardiness in which case low temperature kill damage is a lot more apparent on these species.

An aggressive approach to speed up recovery in the damage areas include a combination of cultural practices.  Core aeration, overseeding, topdressing, and slitseeding may be required.

What Happens to Your Lawn During the Winter Months?

What Happens to Your Lawn During the Winter Months?

PART 5 – WINTER DESICCATION

Add winter desiccation to the long list of what can happen to your lawn during the winter months.  Winter Desiccation takes place when the turfgrass plant is in its dormant or semi-dormant stages and can cause varying degrees of damage severity.  All turfgrass species are prone to winter desiccation if the right conditions persist.  Winter Desiccation occurs when the leaves and other parts of the turfgrass plant are damaged often to the point of death because its roots are unable to supply enough water to keep up with the amount of water the turfgrass plant is losing to the atmosphere.

Prolonged snow coverage during the winter months is considered ideal and certainly helps reduce the risk of desiccation damage.  Snow provides valuable moisture, and acts like a blanket, insolating the turfgrass and covering it from the potential harsh winter winds and unfavorable conditions.   Without snow coverage, preventing damage from desiccation is difficult if susceptible site conditions exist or the weather conditions are less than ideal.  The most severe damage typically occurs when there is no snow coverage and Dry, windy conditions persist.  Generally, the worst affected spots in the lawn are in elevated areas, on exposed slopes, and well drained sites in sandy soils.

The extent of the desiccation damage can range from minor to severe.  If minor damage has occurred, the lawn should recover on its own during the spring when the lawn begins to actively grow and break dormancy.  If major damage has occurred, aggressive renovation practices will be required to repair these areas.  Cultural practices such as Core Aeration, Overseeding, Topdressing and Slitseeding may be required.

What Happens to Your Lawn During the Winter Months?

What Happens to Your Lawn During the Winter Months?

PART 4 – CROWN HYDRATION

 

Crown Hydration continues to be one of the most destructive yet least preventable forms of winter kill that causes damage to a lawn.  Crown hydration commonly occurs during the late winter months when warmer daytime temperatures cause the snow to melt followed by rapid freezing temperatures.  The worst affected areas are in the low lying, poorly drained soils that are prone to standing water.  Under these conditions the turfgrass crown begins to absorb water and become saturated.  Extreme temperature fluctuations cause thawing and rapid refreezing creating ice crystals in the turfgrass plant cells that ultimately rupture and cause plant death.

Predicting when and how extreme damage could be from crown hydration is very difficult when considering temperature extremes and other environmental conditions that the turfgrass is faced with.   There is no exact science that determines under what circumstances crown hydration will cause the most damage or the turfgrasses ability to withstand the susceptibility.  Eliminating standing water by improving soil drainage is one of the best methods to help prevent crown hydration.  Proper fall fertilizing, can also help prepare and improve the turfgrass plants hardiness for the winter months that will reduce the susceptibility to damage as well.

Damage caused by crown hydration can vary from extreme turf death to minor damage where the turf can recover on its own.  As mentioned above, poorly drained soils, and low lying areas are commonly the worst affected that will require the most repair to fix the damage.  A combination of cultural practices such as core aeration, overseeding, slitseeding and topdressing will help with re-establishing the damaged turf.  If drainage or poor soil conditions exist, it is recommend to address these problems to help prevent possible damage from occurring in the future.

What Happens to Your Lawn During the Winter Months?

What Happens to Your Lawn During the Winter Months?

PART 3 – ICE DAMAGE

The effects of Ice coverage can cause varying degrees of lawn damage depending on the severity of the ice coverage, the length of exposure, and the hardiness of the turfgrass species effected.   Where snow coverage is generally considered desirable with the exception of the increased risk for snow mold disease, ice coverage on the other hand is more of a concern and is undesirable often causing more severe damage that requires renovation practices to speed up recovery.

The formation of ice coverage can take place from a number of different factors including freezing rain and rain, poorly drained soil and areas where standing water settles and freezes, and the natural melting of snow and refreezing as ice.   The critical duration of ice coverage before plant death starts to occur is usually somewhere between 30 – 120 days depending on the turfgrass species.  Creeping Bentgrass and Kentucky Bluegrass both have excellent winter hardiness making them less susceptible to winter kill related issues.   Fine fescue and perennial ryegrass have poor winter hardiness and are far more susceptible to ice damage and other winter kill causes.

Long durations of ice coverage significantly increase the chances for severe turf damage regardless of the turf species.  Plant death occurs as a result of ice coverage by the following reasons.  Carbon dioxide gas builds up and becomes toxic when it is trapped under the ice, crown hydration takes place when freezing and thawing occurs and plant cells rupture resulting in death, and the plants hardiness is weakened and reduces its susceptibility to resist damage.

The extent of the turf damage is first visible when the snow and ice melt away, and in many cases this damage may be isolated to only certain areas of the lawn specifically in the lower lying spots and also in the shaded areas where the ice coverage persisted the longest.  If complete death has occurred, an aggressive combination of renovation practices such as slitseeding, topdressing, and core aeration will help repair these areas.  If the damage is sparse and only appears minor, the lawn can usually recover on its own or a light seeding can help speed the recovery up.

What Happens To Your Lawn During The Winter Months?

What Happens To Your Lawn During The Winter Months?

What Happens to Your Lawn During the Winter Months?

 PART 1

Have you ever thought about what happens to your lawn over the winter months when it is covered under ice and snow?  Or wonder why the lawn looks so bad in the spring after the snow melts when it looked so good in the fall?  Or Better yet, all the work you will need to do this spring to quickly get the lawn looking its best again?

To help answer these questions, it is important to outline what can and commonly does happen to your lawn during the winter.  Secondly, determining the what, where, why, when, and how things take place and the damaging effects they can have on your lawn is equally as important.   Understanding this can provide helpful insight on what can be done to help prevent these things from happening next winter, and help determine what course of action might be required to fix your damaged lawn.

Measuring Snow Coverage

Measuring Snow Coverage

Winter Kill is a common term used to describe turf damage that takes place during the winter.  A number of factors and a variety of conditions can contribute to winter kill resulting in moderate to severe turf damage depending on the circumstances.  Most people assume winter kill only happens if and when snow is covering the lawn.  This is not true.  Lawns covered with snow for months at a time certainly do see their fair share of turf damage, but snow alone is not the only factor that causes damage.

Highlighted over the next several blog posts, I will outline some of the most common types of winter damage and the steps to help your lawn recover if and when they do happen.  These include the following:

Snow Coverage

Ice Damage

Crown Hydration

Desiccation

Low Temperature Kill

Snow Mold Disease

Salt Damage

Vole Damage