Frost Damage on Arizona Grass – What Can Be Done?

Although the Phoenix area isn’t associated with the words “cold” or “frost,” in January, February, and even early March, frost damage to plants is still a concern here. You can cover your shrubs and vines overnight, and your trees go dormant if they can’t handle the cold… But what do you do about grass?

Typically, one of several varieties of bermudagrass is used for summer turf, and it fades away to be replaced by Winter Rye for the cool season. You would think that a grass intended for use as winter turf would be immune to frost damage. Well, according to the University of Arizona Cooperative Extension, frost damage can certainly happen to Winter Rye grass. This damage is more common at higher elevations in places like Tucson, but it happens here too.

So, what can you do to prevent this damage? The biggest thing U of A’s Cooperative Extensions suggests is to NEVER step on grass while it’s frozen. Grass blades are small and thin, and if you step on it while it’s frozen, it will suffer huge damage. By noon, the Rye you stepped on will have large, wilted spots in the shape of your footsteps.

You can strengthen your Rye by fertilizing with high-nitrogen fertilizers such as ammonium nitrate or potassium nitrate once in December and once in January. Grass uses up nitrogen quickly, and Arizona soil notably contains barely any nitrogen. Additionally, supplementing with iron can help the integrity of plant cells when it gets cold.

Keep in mind, cold snaps like these don’t happen very often in the Valley. In a typical winter, there are two or three severe cold snaps per year, typically toward the latter half of the season. Keep up to date with weather forecasts and be prepared to stay on the pavement on frosty mornings.

At ELS Maintenance & Construction, we pay close attention to turf conditions to make sure your grass is looking good and going through its natural seasonal cycles as intended. If you know of a community or commercial center that needs new landscapers, contact [email protected] and we can get started!