Onion Diseases You May Encounter, and Dealing with Them

Dan Specialty Crops, This Land of Ours, Vegetables

Onion diseases you may encounter, and how to deal with them. That’s coming up on This Land of Ours.

onion diseases
onion rust

If you plan to grow onions, you’ll likely deal with some of these onion diseases. Such as Yellow Onion Dwarf, Purple Blotch, or Pink Rot.

onion white rot mold

Damping-Off Disease is another issue you may encounter when starting your seedlings. It’s common when onions are planted outdoors too early and are exposed to cold, damp conditions. You can’t fix this once it sets in, but you can try to prevent it by starting seeds in a soil-less starting medium, such as perlite or vermiculite and coconut coir.


As far as onion diseases go, Onion White Rot is one of the most insidious. This fungal disease can lurk in your soil for up to 20 years! You can identify it by the fluffy white fungal growth around the bulb bases and stalks, as well as wilted, yellow leaves. There’s no real treatment for this issue. Your only option is to destroy the crop, dig out the soil and treat it with hardcore fungicide and solarization, and avoid planting any alliums there for at least two decades.

Listen to Cathy Isom’s This Land of Ours program here.

Onion Diseases You May Encounter, and Dealing with Them