Project Garden

Now that we are deep in the winter season, the beauty of a glistening frost can mask the potential dangers it poses to the health of our lawns. Heavy frost occurs when the water vapour in the air freezes upon contact with surfaces that are at or below the freezing point. This phenomenon can have a significant impact on grass and lawn health.

Grass blades are composed of cells filled with water. When temperatures drop below freezing, the water inside these cells can freeze, causing the cells to expand and rupture. This damage is not immediately visible but can become apparent as the lawn thaws. The grass may appear wilted or discoloured, and in severe cases, the blades may be unable to recover, leading to patches of dead grass¹²³.

One of the most common issues associated with heavy frost is the development of snow mould. This fungal disease thrives under the cover of snow and becomes evident as the snow melts, leaving behind grey or pink patches on the lawn12. Snow mould can weaken the grass and make it more susceptible to other diseases and pests.

Another concern is the physical damage caused by foot traffic or equipment on frosted grass. The frozen blades are brittle and can easily break, leading to long-term damage that may not fully heal until the following spring¹³.

Protecting Lawns in the Winter Season

To mitigate the effects of heavy frost and protect lawns during the winter, several preventative measures can be taken:

1. Avoid Walking on Frosted Grass: Keep off the lawn when it’s frosted to prevent breaking the brittle grass blades¹³.
2. Proper Fertilization: Applying the right fertilizer before the onset of winter can help strengthen the grass and make it more resilient to frost and snow mold¹.
3. Aeration and Dethatching: These practices improve air circulation and reduce moisture retention, which can help prevent snow mould and other fungal diseases².
4. Mulching: A layer of organic mulch can act as an insulator, protecting the grass roots from extreme cold and maintaining stable soil temperatures⁴.
5. Winterizing Fertilizers: Applying a winterizing fertilizer or potassium spray can enhance the grass’s cold tolerance and strengthen the plants before dormancy⁵.
6. Snow Management: Gently remove heavy snow from the grass to prevent damage and matting. Use a broom rather than a shovel to avoid harming the grass blades.
7. Tree and Shrub Care: Mulch around trees and shrubs to provide extra protection and control erosion and water loss⁶.

By understanding the impact of heavy frost and implementing these protective measures, we can help ensure that our lawns remain healthy and vibrant, ready to flourish once again in the spring.