tiny brown spots on Romaine leaves - Ask Extension
I have romaine lettuce, kale, cabbage, and leaf lettuce planted through landscape fabric and covered with lightweight floating row covers to keep out ...
Knowledgebase
tiny brown spots on Romaine leaves #633417
Asked May 09, 2020, 2:11 PM EDT
I have romaine lettuce, kale, cabbage, and leaf lettuce planted through landscape fabric and covered with lightweight floating row covers to keep out the bugs, bunnies, and deer. The leaf lettuce, kale and cabbage look fine, but the romaine lettuce, particularly one plant, has developed tiny brown spots on the leaves (pictures attached}. I don't see any bugs on the plants. Any ideas what is causing this and how to stop it? Thank you.
Charles County Maryland
Expert Response
Hi- we think this may be edema which seems to be occurring more frequently this year. Very small, slightly raised areas develop on leaves, burst, and appear as brown spots. It's caused by excess soil water, a small root system, and cloudy, cool, dry weather. The plant cells take up more water than they can transpire. Romaine may be more susceptible than leaf lettuce. Cabbage is fairly susceptible. The landscape fabric is helping to hold water in the soil which may be a contributing factor.
https://extension.umd.edu/hgic/topics/edema-vegetables
Jon
https://extension.umd.edu/hgic/topics/edema-vegetables
Jon
