Although Winter can be tough on us as humans, it can also have severe consequences for your lawn.  The layer of snow and ice laying on top of your grass during Winter creates a haven for fungus to thrive, despite the frigid temperatures.  Once the Spring thaw-out begins, things begin to cascade into even more dire circumstances for diseases to develop and regenerate.  Here we discuss two common Winter lawn diseases and how to treat and prevent them.  To learn about some other lawn problems we suggest you read our post here : 6 Common Lawn Problems and How to Fix Them


Gray Snow Mold

This disease appears in temperatures between 32-45 degrees F.  It is caused by snow cover over wet, unfrozen ground.  Usually following snow melt in late Winter, you can start to see signs of this fungus take over your lawn.  From far you will notice patches of dead, bleached colored areas, up to several feet in diameter.  It can sometimes be mistaken for patches of road salt due to the time of it’s emergence.
Getting a closer look can help you to really determine if you have this fungus starting to take over your lawn. Upon closer inspection you should see water-soaked, matted circular areas.  These areas will be covered with gray fungal “thread-like” structures.  This is the fruiting bodies of the disease, and help it to spread. If you happen to come upon this disease during a drier period you will notice grass blades are brittle and gray to silver in color.



Pink Snow Mold

Pink Snow Mold grows in similar temperatures to it’s aforementioned counterpart, Gray Snow Mold.  It will also be caused by snow cover, but usually snow cover at a heavier rate.  From far you will see orange-brown circular patches, but much smaller in diameter.  Pink Snow Mold patches usually grow only to about 2-10 inches in size.  Close up you should see a ring of pink fungal structures, which give it it’s name.  These fungal structures help this disease to reproduce and spread.  The appearance of this disease, and its associated spores, indicate intervention is required to prevent a larger problem in Spring.

Get your garden and flower beds ready for Spring by reading here: Spring Gardening Tips; It’s Never Too Early To Make Plans.



Treatment & Prevention

These diseases affect all cool season grasses, especially perennial Rye grass varieties. The best treatment for both of diseases is prevention through cultural practices.  Here we have some well known practices for preventing Winter mold in your lawn:

  • Avoid excessive Nitrogen Application after October
  • Prevent Snow compaction
  • Maintain low soil pH (5.7-6.3)
  • Mow grass at lower height for final Fall mowing to prevent excessive top growth
  • Use resistant varieties


Sometimes these diseases can get beyond control and require the use of an approved Fungicide to eliminate and prevent spreading.  We recommend using a licensed professional with knowledge in identifying and treating these types pests properly.  If you would like to discuss this or other lawn issues you may be having feel free to call (860) 222-7171 or request a quote HERE.


-Mike Ortiz (Green Team LLC)

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