Since I do not have much experience growing butternut squash, this is a new-ish problem for me. I have encountered this problem with some tomatoes, plums, and cherries, but I did not know it could happen with butternut squash too.
Four fruits burst in the last week: two lengthwise, two across. The one in the picture broke almost all around; a centimeter more and it would essentially fall off.
I guess this is because the shell hardened prematurely in the heat, and then the fruit grew too quickly after the rain. I had to harvest this one prematurely, and I gave two others to my neighbor because they should be processed ASAP, and we cannot do that right now. The one that burst first has only a small crack that dried out, so I left it on the plant for now. But I will harvest and process it at the earliest possible time too.
I do not think there is anything I can do about this. Even if I watered the plants during the heatwave more than I did, it would not help; they could not take up the water during the day fast enough anyway.

























































