Leaf Rot

Leaf rot causes crisp, leafy greens turn brown and mushy.

Rotting lettuce (Rasbak) CC BY-SA 3.0

Your spinach, endive, escarole, lettuces, mustards, and Swiss chard are all susceptible. So are your lentils, strawberries, beans, peas, okra, and many cucurbits.


What is leaf rot?
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You’ve seen it in your refrigerator. You place a fresh head of lettuce in the crisper drawer. The next time you look, leaves have turned brown and mushy. What happened? What happened is fungi or bacteria found a hospitable location and started reproducing and feeding. Rotting is the breakdown of complex structures by those tiny life forms. 


Causes of leaf rot
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Leaf rot can be a case in which leaves were exposed to too much moisture and decomposition set in. Leaf rot can also be a symptom of any number of fungal or bacterial diseases, most often caused by Fusarium, Pythium, Phytophthora, and Rhizoctonia. These leaf rot diseases include cherry mottle, cucurbit wet rot, carrot leaf rot, lentil leaf rot, pigeonpea leaf rot, and white mold.


Like most rots, moisture is a critical component. Allowing water to sit on your leafy greens invites trouble, as does saturated soil.


Preventing leaf rot

Rather than losing your leafy greens and other garden favorites to leaf rot, there are steps you can take to prevent this problem. First, healthy plants are better able to protect themselves, so select plants best suited to your microclimate and avoid overwatering. Good drainage will also help prevent conditions that lead to leaf rot. Instead of overhead watering, use drip irrigation, a soaker hose, or furrow irrigation. 


​If leaf rot does occur, dig up infected plants and throw them in the trash. This will reduce the chance of neighboring plants suffering a similar fate.​