I am disappointed to report that powdery mildew has taken hold of our pumpkin patch and spread to the butternut squash. Next year—and it will be back next year—I will recognize the first signs and take offensive action immediately. This season, however, I didn't know what it was at first, I played the wait-and-see game, and now we're playing aggressive defense and hoping it's not too late.
I saw small white spots on some of the pumpkin leaves and wondered if they were getting too hot throughout these very hot, very sunny days. Perhaps if I give the leaves a little water, I thought, while watering one evening. Big mistake! What powdery mildew loves the most is hot, humid weather and wet leaves overnight. So, the dusty white spots spread to more leaves and completely covered some leaves, and then I finally Googled the description and diagnosed the problem.
I already had a spray bottle of organic fungicide for controlling the same malady on our apple saplings (why didn't I realize?!), so the next evening, I took action. Some gardeners will say you must remove all affected plants. Whole plants! I couldn't do it. I had baby pumpkins to try to save. I clipped off the worst-affected leaves and bundled them in a plastic bag, which went into the trash—not into the compost where they would only harbor the mildew until it could spread to anything the compost later touched. And then I sprayed the remaining affected leaves (tops and undersides, which were sometimes worse) with fungicide until the bottle ran out. I went to the hardware store and bought three more bottles and went back two evenings later to clip even more leaves and finish spraying the rest of the pumpkins, squash and—oh no!—the cucumbers too, until I had about two-thirds of a bottle left for future attacks. (You must wait at least four weeks between treatments.) The pumpkin patch had it the worst and looks pretty sparse now. I hope that the poor baby pumpkins, some on nearly leafless vines, continue to grow.
And, in much the same way that a person with a compromised immune system is more susceptible to further infection, a diseased plant is more vulnerable to harmful insects (and vice versa). It's no surprise, then, that while I was lifting the leaves to spray their undersides, I came across a small cluster of bronze pellet-shaped eggs. Squash bugs! Those ugly, flat-backed, brown bugs that like to suck the sap right out of vining vegetables. I only found the one cluster, which I removed by tearing off that portion of the leaf and trashing it with the mildewy leaves (I also crushed the eggs and soaked them with fungicide for good measure), but now I must be on the lookout for other eggs under the leaves as well as other signs of squash bugs, like yellow spots and wilting vines. Great. Stay tuned for a progress report.
Let's end on a positive note: We have already harvested nine cucumbers and used some for a delicious cold soup that I may post later; we have three good-sized regular watermelons and two palm-sized giant watermelons, as well as a few teeny tiny baby fruits in our very viney watermelon patch; and tassels are finally popping up out of our corn, resulting in fresh pale silk strands spilling out between the leaves of one stalk so far. Exciting!