Have you ever had those straw-brown patches in your lawn and wondered what did I do wrong or, why is my grass dying?
Have you heard of Ascochtya leaf blight? If you haven’t, that’s ok. Until Leaf blight takes toll on lawns, was written by Sarah Browning this past week in the Lincoln Journal Star, I had no clue leaf blight existed.
Sarah shares excellent insights to the straw-brown patches appearing on Nebraska lawns. I’ve seen those patches in Nebraska, even in my own lawn. However, never batted an eye as to what the causes my grass to look so beat up. Sarah goes into great detail about Ascochyta leaf blight, providing a better opportunity for you to identify symptoms, causes, and management techniques in case this fungal foliage disease ever sneaks its way into your lawn. (Browning, S. 6.10)
Here are a few snips of Sarah’s article.
Typical symptoms include irregular straw-colored patches that appear very quickly. Severely infected grass blades are killed from the tip all the way down to the crown, causing the grass to appear dead. But although the grass appears completely dead from a distance, closer inspection shows the leaf blades are only dead about one-third down the length of the blade. Leaves show a straw-colored tip dieback, an abrupt margin between dead and healthy tissue, and a reddish-brown border at the base of the dead section.
What causes it?
Ascochyta is a stress-induced infection is favored by low fertility, poor turf management and/or weather conditions that weaken turfgrass plants. Damage can appear any time of year but is most common during late spring and early summer when weather conditions shift from cold and wet, to hot and dry.
The good news is lawns affected by Ascochyta usually recover almost as quickly as they were damaged. This disease may appear severe and affect large areas of turf but seldom is the damage permanent. Since the plant crowns are not killed, they regenerate new foliage within about two weeks. During this time dead leaf tips are mowed off and the damage disappears.
Additional tips for good turf management practices to aid your lawn recovery include the following.
• Irrigate in the early morning hours
• Don’t overwater the turf; provide deep infrequent irrigation
• Manage thatch and promote water infiltration through soil aeration in spring and/or fall
• Don’t allow the turf to go into drought/moisture stress during the growing season
• Avoid excessive applications of nitrogen by using slow-release nitrogen fertilizers
• Mow on a regular schedule and make sure your mower blade is sharp
• Avoid mowing during wet weather
• Maintain your lawn at 2½ to 3 inches in height
The complete article: Leaf blight takes toll on lawns
Browning, S. (6.10). Lincoln Journal Star. https://journalstar.com/lifestyles/home-and-garden/sarah-browning-leaf-blight-takes-toll-on-lawns/article_c528721b-e25a-566a-a954-ff89f114fa50.html. (retrieved 06.12)