It’s a nature battle as old as time.
Grass versus Frost.
As long as there has been grass, there has been frost putting a cold hard chill on it come late autumn. Frost arrives when water in the atmosphere settles and freezes.
This is where the issue develops between frost and grass. Thankfully, it’s a much gentler dispute and battle for supremacy than oil vs. water or the Hatfields vs. the McCoys.
Typical grasses used in Iowa lawns are constantly trying to draw water through blades of grass. When frost settles on grass, the grass is still trying to get water.
But instead, frost can freeze inside grass, killing grass in some spots.
Frost, as Homes & Garden’s Jill Morgan notes, “can have a detrimental effect” on lawns and especially young grass.
How can you help your grass avoid frostbite this fall and winter?
The Nature of Frost
By definition, frost is condensed water that has frozen overnight. Not snow. Not ice. Just troublesome frozen water.
The magic number for frost to form is 32 degrees. A lawn’s first run-in with frost — like the slick sub-30 degree mornings that chilled Eastern Iowa in late October — can leave it looking beat up, bruised and a lifeless brown.
The good green news: Your grass will rebound and come back strong if you follow the Rules of Lawn Frost.
Don’t Walk On Your Lawn
The ice inside and outside can become microscopic daggers. Stepping on a frost-covered lawn can cause those daggers to further damage the grass blades.
Don’t turn your lawn into a crushed popsicle by stepping on it after a frost. Take the long way around your grass and don’t even think about driving on it.
Water Before the Freeze
Sure it sounds crazy, but your grass drinking high quality H2O before a frost can enable moisture to slowly evaporate overnight. This will cause friction and heat around the grass blades.
As the night air temperature drops, your grass will keep a higher temperature. The all-important result: Your lawn won’t reach a freezing temperature and avoid plant cell wall damage.
Cover Newly Sprouted Grass
Newly planted grass isn’t as strong as its older siblings and is most vulnerable to severe frost damage. Cover new grass with either a tarp or horticultural fleece. Be sure to remove the cover early the next morning to allow sunset and air to rehydrate your grass.
Do Not Plant Just Before a Frost
Trust us, the frost will make your time and effort planting new grass just before a cold snap all for naught.
“Planting before a frost can cause plant loss,” Russell Taylor of Live Earth Products told Home & Gardens. “If the seedling has not established enough roots and food reserves, it will not survive.”
Be sure to also mow your grass to 2-3 inches high when cold weather approaches to give it extra tissue and insulation for its grown
Frost and Grass have been battling for centuries. As The Ohio State University’s Beth Scheckelhoff stresses, frost “can injure or kill sensitive” grass.
But smart frost defenses can enable your grass to win the battle with its eternal archrival this fall and winter.