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
- Earlier this season we sprayed with Dursban, can we still eat the fruit?
- How do I get rid of morning glory?
- I still have a lot of green tomatoes on the vine but it looks like frost is getting the better of them (the vines, not the fruit yet) the past few nights. I plan on using the tomatoes for Chili Sauce. If I pick the green tomatoes are they going to ripen inside? Is there a better way to get them ripened to use for chili sauce?
- I want to find out about the master gardener program, my computer wont let me link, can you give me more info or a different link address or something. I want to know sign up date class times, location, cost and if aid is available. Thanks so much for your help.
- Do you have information on water-wise annuals?
- How do I store my summer bulbs?
- What causes plants to look dirty and lose their green color during the heat of the summer? One culprit is spider mites.
- How can I store my fresh garden fruits and vegetables?