Ask a Question
Notify Me On Question Update
Email this Question
My squash plants turned white and wilted this summer. What happened?
Rate This FAQ
Your squash plants were infested with a disease called powdery mildew, which can be common in
Initial infection occurs via airborne spores from neighboring plants. The disease can develop very quickly once infection occurs, and is first visible on the shaded undergrowth, where leaves are dense, light is low, and humidity is moderate. The infected leaves will turn yellow, wither, and die.
The best way to manage powdery mildew in the future is prevention. Once infection has occurred, there is no way to “cure” that plant. Use powdery mildew-resistant cultivars of squash and other cucurbits. Examples include ‘sungold’, ‘sunray’, and ‘success’ summer squashes, ‘payroll’ and ‘ambassador’ zucchinis, and ‘table star’, ‘bugle’, and ‘celebration’ winter squashes. In fall, remove and destroy all infected plant material—do not till the debris from your vegetable garden into the soil. In the spring, start your plantings in a healthy, rich soil, and use wide spacing. During the growing season, improve air circulation around the plants by keeping the area weed-free, and avoid over-head watering and excessive fertilization.
Monitor your plants throughout the summer for infection. If you notice any spotting or curling of the foliage, or circular white patches on the leaves, remove the leaves or plant. At this time, start applying preventative fungicide sprays every 2 weeks. Examples include neem oil and sulfur. Research has shown that a combination of baking soda and horticultural oil can prevent infection (1 tbs. baking soda and 2.5 tbs. oil in one gallon of water).
Submit Your Suggestion
Other Questions In This Topic
- Do you have information on water-wise annuals?
- Tomato tutorial
- What is the best way to get rid of morning glory in my lawn and garden?
- I would like to plant vegetables in containers this winter. What can you tell me about indoor gardening?
- I planted tomatoes last weekend because it looked like we were going to have warm weather, but yikes! it says it will snow tonight. How can I protect my little tomato plants?
- I was wondering if you could tell me where to find the planting schedule for Utah. Could you also tell me gardening plants that tend to grow better than others here in Utah? Thank you
- When can I cut back my tulips and other spring bulbs?
- Is there some place in the Salt Lake area where I can donate my garden snails? I read that thrushes and ducks (along with many other critters such as beetles, which I don't want to introduce into my garden) will eat snails. I know I could kill the snails using a variety of methods, but it seems like somebody (not me!) might like to eat them. Ideas?