Winter Squash, Fungus, & Status


11/7/2019 – On 10/24/2019 I began spraying the winter squash for fungus that was damaging leaves. I should have sprayed the initial small areas 3-4 days earlier before it spread. It spread very quickly.

Acorn squash on the right side is leafless.

I should have begun spraying Mancozeb much sooner as a preventative.

Mancozeb seemed to stop the spread and some of the plants put on new leaves. Initially, I also sprayed on half the plants Bonibe’s Copper fungicide that was already mixed in the sprayer. The plants that were sprayed with the copper did not seem to do as well as those sprayed with Mancozeb.

Likely the daily watering during the weeks of no rain in September did not help.


All ten of the small acorn squash that survived the fungus killing the leaves have been picked. The Table Ace Acorn Squash was the hardest hit by the fungus.

The spaghetti squash suffered from the fungus but has a number of fruit. Although the reduced amount of leaves will likely cause them to remain small.

The butternut squash was also hit hard by the fungus but has a lot of smallish fruit but less than half its leaves.

We thought the pumpkins had all died but realized that odd-looking acorn squash was really a pumpkin. Then several more appeared. The pumpkin plants were not as damaged by the fungus as was the winter squash.

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