Answer: You can help prevent mildew on the leaves of pumpkin plants by making sure the plants are in the sunniest area of the garden, there's adequate air circulation, and you avoid overhead watering late in the day so the leaves have a chance to dry out before nightfall. You might want to remove some of the vines as they develop to give the remaining vines and fruits ample exposure to sunshine and good air circulation. Sometimes the cooler evening temperatures in the early fall will make the plants more susceptible to mildew. If you find mildew on the leaves late in the season, cut them off and destroy them so the problem doesn't spread to other leaves.
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