One of the most crucial steps of growing onions successfully is keeping them healthy and disease free. Detecting the early signs of diseases in onions starts with inspecting the foliage.

Signs of disease in onions

Almost all diseases start with the symptoms of small white sports that are surrounded by a green halo. The centers of the spots often are tan, making it difficult to distinguish between fungal spores and damage from insect feeding, mechanical damage, or damage from wind or herbicide injury. These lesions expand with age and when numerous, may cause the leaf tips to dieback. Eventually, leaf death will result and those severely effected plants will develop a blighted appearance. Bulb size will be reduced because growth is reduced by leaf loss.

onion blight

Staying ahead with a preventive fungicide program is the key to disease prevention. The fungus can over-winter in infected plant material or may survive in the soil. Wet, warm weather can spread the disease rapidly. Orienting plant rows and increasing the spacing between plants help reduce the time the leaves stay wet and results in less disease incidence and severity. Deep plowing and crop rotation will help reduce the numbers of the spores in the soil.

oxi date

We have several fungicide options that we recommend. Mancozeb Fungicide with Zinc and OxiDate Organic Fungicide. Both of these products keep disease out of the foliage during the growing stages and will also help prevent any diseases that will cause rotting in storage ensuring your onions store to their maximum potential. To keep your onions disease free, we suggest putting your onions on a bi-weekly preventive treatment plan. If you notice early signs of disease, these products can be used weekly as needed.

To see our entire selection of growing products available or place your orders, visit our  Web site . You may also contact Customer Service at (830) 876-2430 or email We look forward to another season of providing the highest quality onion plants for you.