More
    Categories

    Powdery Mildew

    Related Articles

    There are many different powdery mildew fungi. The fungus spores overwinter on fruit trees. In spring, the fungus begins to grow, and spores are released to travel on the wind to young leaves. Powdery mildew thrives where cool nights follow warm days. Insufficient sunlight and poor air circulation favor the development.

    Target Plants

    Bee balm, begonia, clematis, dahlia, euonymus, hydrangea, lilac, pansy, phlox, rhododendron, rose, sunflower, zinnia, bean, grape, pea, potato, pumpkin, squash, strawberry, tomato, apple, dogwood, peach, crepe myrtle, maple, oak, and sycamore trees.

    Signs

    A white or gray powdery fungus appears on foliage and flowers. Round, white spots on upper leaf surface expand and merge, covering both sides of leaves. Infected leaves turn yellowish-green to brown. New growth may be stunned, curled, and distorted. Infected blossoms may not set fruit; fruit may develop a rough skin or be covered with the powdery fungus. Fruit drops early or is dwarfed.

    Prevention

    Some weeds get easily infected with powdery mildew, such as henbit. Plant resistant selections. Give plants sufficient light and air circulation. Water plants from underneath rather than above to keep leaves dry.

    Control

    Reduce nitrogen fertilizer. Pick off and destroy infected leaves and flowers. Spray ornamentals with horticultural oil, triforine (funginex), thiophanate-methyl (Thiomyl, Domain), azadirachtin (Neem), or triadimefon (Bayleton). Spray fruits and vegetables with wettable sulfur or horticultural oil. Discard infected flowers of annuals and leftover produce in fall.

    Video Credits: California Garden TV – Advice for All Climates
    Image Credits: Pollinator, WikiMedia

    Categories

    Other Topics

    Rocks and Coral For Marine Aquarium

    Naturally, you don't want a bare tank with just water and sand. Correctly placed pieces of rocks and coral will not only improve the appearance of your...

    A Cat Who Wiped Out An Entire Bird Species

    Overview There was a cat named Tibbles who was owned by a lighthouse keeper. The cat became infamous...

    Norwegian Lundehund

    History & Overview The Norwegian Lundehund, or Norwegian Puffin Dog, originated in Norway around 5,000 years ago where...

    Drestructive Digging, Barking, Chewing

    Overview Undesirable behavior might be the biggest reason for surrendering pets to shelters in all countries. More companion...

    Northern Pygmy-Owl

    Appearance The Northern Pygmy-Owl (Glaucidium gnoma) is tiny indeed no bigger than a good-sized-sparrow. It has two distinctive...