Red spots on my Rhubarb leaves - Ask Extension
I've been seeing more and more leaves affected by red spots on my otherwise healthy looking rhubarb. What is this and is this something that a require...
Knowledgebase
Red spots on my Rhubarb leaves #839671
Asked July 08, 2023, 6:26 PM EDT
I've been seeing more and more leaves affected by red spots on my otherwise healthy looking rhubarb. What is this and is this something that a requires destroying the plants, a treatment, etc. Can the stalks be safely harvested?
Olmsted County Minnesota
Expert Response
You are seeing a common fungal disease of rhubarb. Harvest the stalks that aren't spotty. Stalks with spots will not keep well. It is ok to eat the rhubarb. Dispose of infected leaves in the organic waste not your compost pile if you have one.
https://extension.umn.edu/vegetables/growing-rhubarb#diseases-923465
https://extension.umn.edu/vegetables/growing-rhubarb#diseases-923465
Thank you so much for your response. As a nurse who loved my microbiology classes, my curiosity begs me to ask the name of this fungus.
Also, I have been pulling out and tossing the stalks that have the spotted leaves, but didn't realize it was ok to use the stalks without spots. Great news! Thanks!
I think this fungus started late last year, and is worse this year. I assume I will need to make sure and discard all the stalks and leaves after the first freeze to minimize any fungus remaining on the ground and affecting next year's plants. Should I pull all the mulch and replace the mulch?
Is there a safe organic treatment for the fungus, the ground?
Thanks again!
Linda Anderson
There aren’t any good fungal treatments for soil other than solarization and that will kill your plants. Sanitation (discard stalks and leaves) , reducing leaf splash from watering, letting the soil dry between waterings and no overhead watering will reduce the infection rate. Fresh mulch each year is a good practice and this years mulch should be broken down by fall. Bark mulch is one of the few mulches to last a season unless the mulch is put down too thickly.
Each year brings its own challenges because the weather changes. Some years promote fungal diseases and others don’t. Makes gardening always interesting.
Each year brings its own challenges because the weather changes. Some years promote fungal diseases and others don’t. Makes gardening always interesting.
Thank you so much for you time and the very helpful response. Your time and expertise is greatly appreciated!!
Sincerely,
Linda Anderson
You are welcome. Enjoy your harvest.
