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Kale Leaf Rotting #679134 - Ask Extension


Kale Leaf Rotting #679134

Asked January 14, 2021, 11:38 AM EST

My friend is a long-time gardener and this year his kale patch was attacked by some disease that rots the leaves and eventually rots to the crown and then destroys the stalk. He wonders if it is related to harlequin bugs as they showed up in large numbers in his garden this year. I have attached some photos for your examination. My friend has asked me to help him find an answer. You guys have given me great solutions to my own garden problems in the past, so here I am with a request!

Howard County Maryland

Expert Response

You are a good friend!

It's possible that harlequin bugs killed the top growth if the infestation was significant. Here is our page on Harlequin Bugs, which will offer help with monitoring and management of the pest for the future:  

Rotting of the crown could have been due to secondary disease pathogens as the plants declined. 

It's also quite possible that a primary infection occurred to the roots and/or crown. We had above average rainfall in many areas during late summer. Wet soil under the mulch may have also reduced gas exchange and oxygen levels in the soil.


Christine McComas Replied January 14, 2021, 1:03 PM EST

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