Powdery Mildew

Fighting powdery mildew requires a multifaceted approach.
powdery mildew 
Powdery mildew is a foliar disease that attacks many species of plants but is especially prevalent on cucurbits such as pumpkins, melons, cucumbers, and squash. It also attacks tomatoes, peppers, and flowers and is a real threat on many rose varieties.
You can recognize powdery mildew easily. It appears as a light cottony film on the surface of a leaf, looking almost as if someone had spread powder across the leaf.
Powdery mildew can survive at a wide range of temperatures but is always a threat under one specific environmental condition: high humidity.
powdery mildew on back of pumpkin leafWhen fungal structures called spores - tiny microscopic seeds - land on leaves, they recognize the leaf, germinate, and send finger-like structures called hyphae down into the leaf to start the process of feeding and growing.
Blocking the recognition of the leaf by the spore is one natural way of stopping powdery mildew from taking hold. If the spore doesn't recognize the leaf, it won't germinate, and the disease does not form.
By keeping a small film on the leaf surface that contains natural compounds that block the signals, the plant stays protected.
You can further help the plant fight off powdery mildew by strengthening surface cell walls with higher levels of available calcium. Stronger cell walls are harder and thus require more time and energy to penetrate.
Once the disease begins to grow, it gets much more difficult to control.
Typically plants must maintain high levels of copper, manganese, and zinc to fight off powdery mildew from the inside out. Many fertilizers today do not include these elements, while others carry them in forms that are nearly impossible for a plant to take in and utilize. Putting these elements into the soil early in the life of a plant will help soil microbes aid in releasing the elements to the plant. This assures the plant of having higher day-to-day levels of copper, manganese, and zinc.
Alternatively, by using some newer, environmentally friendly and award winning technology, you can spray copper, manganese, and zinc on the plant weekly. This enables the elements to pass safely and effectively through leaf surfaces, guaranteeing the plant of getting proper nutrition consistently throughout the season. In essence, you're keeping the plant healthy from within.
Maintaining high levels of available calcium in the soil - calcium that can be picked up by plant roots - will strengthen those roots as well as the plant leaves and encourage more-vibrant growth. Proper calcium levels also assist plants in maintaining higher sugar levels, called brix, to fend off the stress of disease attacks.
powdery mildew on pumpkin leafTaking on a quick leaf killer like powdery mildew requires a multifaceted approach and a consistent program. You'll tackle powdery mildew successfully when you give both soil and plant the "tools" - the nutrients - they need to communicate well with each other. That communication is vital to the plant?s daily protection. And it's absolutely critical to winning the war against disease.
To view a brief, field identification video of powdery mildew, click here.
Need further help with powdery mildew? Contact Garden Vigor.