Don’t forget the Harvey County Fair begins on August 4th! Flower, Garden and crop exhibits may be entered on Saturday August 5th from 8:00 AM until 11:00 AM. Contact the extension office to register for an exhibitor number by calling 284-6930. If you registered last year you will be using that number again. Bring your best and see how it stands up to the rest!
Powdery mildew starts as individual spots that resemble snowflakes but rapidly coalesce to cover the entire leaf so that a plant look like it was dusted with flour. Though common on other plants such as lilac and bee balm, it has been relatively rare on peony until the last few years.
Poor air movement and shade make the disease more likely. Growing peonies in full sun with good air movement will help minimize the disease. Fungicides can be effective if applied before infection has occurred. Therefore, heavily infected plants should not be treated as the treatment will be ineffective. Fortunately, the disease should cause no lasting damage to the plant.
Remove and discard (or compost) infected plant material at the end of the season. Look for individual spots to appear the following spring and then apply a recommended fungicide before the disease has spread. Suggested fungicides include myclobutanil (Eagle, Spectracide Immunox, Immunox Plus, Fertilome F-Stop Lawn & Garden Fungicide), propiconazole (Banner MAXX, Fertilome Liquid Systemic Fungicide) or tebuconazole (Bayer Disease Control for Roses, Flowers & Shrubs).
Harvey County Extension
800 N Main, Room 11, P.O. Box 583
Newton, KS. 67114 316-284-6930