Don’t like the weather, wait 15 minutes and it will change. This is a familiar saying to those of us who live in Colorado, but frequent weather changes can be unkind to our landscape.
While the 2015 growing season has been one of the most seasonable in years, thus far it’s been marked by hot and dry weather with periodic monsoonal weather patterns. This provides perfect conditions for a fungal lawn disease called Ascochyta (as-co-kite-ah) leaf spot.
During the heat spells this summer, many lawns became drought stressed. The weather then quickly changed to cool and humid as the unusually wet monsoon season moves in. Nearly overnight, the affected grass turns into a straw-like color. The grass patches appear dead, however only the grass blades themselves are affected by the fungus– the roots remain unharmed.
In Colorado, ascochyta appears in the spring and summer months. The spring infections typically recover quickly in the cooler weather. In contrast, summer infections are slow to recover and may only do so with cooler fall temperatures and proper lawn care.
What You Can Do:
- If not already completed, have your lawn aerated.
- Set you mower to a height of 2 ½ to 3 inches. Take time now to make sure your mower blade is sharp.
- Continue with a balanced fertilization program. Do not increase fertilization to promote recovery.
- Check your irrigation system to ensure complete coverage. Water the affected area with more water less often. Limit your watering to the early morning hours so that the grass plant will dry quickly.
- Applying a soil conditioner that promotes water penetration may also promote recovery.
To help prevent a similar occurrence later in the summer, sharpen you mower blade monthly and check your sprinkler coverage frequently. Increase and decrease your irrigation schedule as the summer temperatures change.