Protecting Impatiens from Downy Mildew

Impatiens are vulnerable to a variety of pathogens and are most at risk of infection during greenhouse production. One of the most damaging diseases is impatiens downy mildew (IDM). With effective cultural practices and a powerful rotation management program, growers can confidently cultivate plants without the disruption of IDM.

Spotting Impatiens Downy Mildew

The most effective way to stay ahead of IDM is by monitoring crops closely to catch signs of infection early before it becomes detrimental to the plant’s health. Common initial symptoms often include:

Syngenta photo. Rechcigl, 2018.
  • Stunted plant growth
  • Distorted, wilted or downward curled leaves
  • Leaf discoloration or spotting, especially along the veins
  • Small emerging leaves
  • Malformed flower buds
  • Pale foliage with yellow, tan or red blotchy areas
  • White or light gray/purple fuzz on the undersides of leaves

Proven Methods for Prevention

The Impatiens Agronomic Program from Syngenta can help prevent a wide range of common diseases during impatiens production, including IDM. The program includes products with various modes of action to support resistance management and preserve valuable chemistries.

This rotation includes an application of Segovis® fungicide, formulated with systemic properties that offer long-lasting control when applied as a drench or foliar spray at low use rates. Equipped with a unique mode of action and active ingredient oxathiapiprolin, Segovis is crucial for maintaining control of diseases like IDM.

Learn more about this fungicide at GreenCastOnline.com/Segovis and more agronomic program solutions at GreenCastOnline.com/Solutions.

All photos are either property of Syngenta or are used with permission.

© 2025 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration status and proper use. GreenCast®, Segovis® and the Syngenta logo are trademarks of a Syngenta Group Company. All other trademarks are the property of their respective third-party owners.

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