Why Squash Leaves Turn Yellow

Question

I read your article, says if the plant is stressed for the most part, or other things mentioned..I was wondering, I planted 2 yellow squash plants in one 25 gallon planter and was going to separate them before they got too big, but I got sick and didn’t get to it, now they are way too big to transplant. Could this be a reason too that they may be stressed? No gooey sap coming out if leaves, just not sure about the bug u mentioned. Thanks for your help.(3rd pic is a 3rd plant, has white powdery look on leaves, but only that one? Fungus?

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Answer 1

The yellowing leaves could be from over or underwatering so make sure they get enough water. Since they are in pots, frequent watering can also leach out the fertilizer, which can cause yellowing. And if the roots have filled the container, it can prevent uptake of nutrients. You can repot them into larger containers if they are rootbound.

Check for the squash vine borers or squash bugs. Some of the leaves are drooping too. The third pic could be powdery mildew if it is like powder. These articles should help:

https://www.gardeningknowhow.com/edible/vegetables/squash/squash-pests-identifying-and-preventing-squash-vine-borer.htm

https://www.gardeningknowhow.com/plant-problems/pests/insects/squash-bug-control.htm

https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm