What is happening with my cucumbers?

Asked August 25, 2020, 11:54 AM EDT

I've planted cucumbers for the first time this year and they are not looking good. What might be causing it and what can I do? Most of the leaves have turned yellow and brown and some have died. The few cucumbers I have so far seem OK. The leaves at the end of the vines still seem green. And I'm not sure if it has spread to my zucchini plant? Pictures attached.

Livingston County Michigan

1 Response

Thanks for the question. This has been a tough year for cucurbits. Yellow leaves can result from insect damage, lack of water, bacterial wilt, etc. Depleted nutrients can also cause yellowing, An application of 5-10-10 fertilizer could improve the color. Hot temperatures and lack of rain necessitates a lot of watering of cucumbers but too much water can also cause yellowing. Looking at the leaves in the last picture I would check for spider mites. Keeping pest populations of cucumber beetles (vector for bacterial wilt) and squash beetles (leaf damage) will help. Check the backs of leaves for dirty greyish fuzz spots (downy mildew) this can wipe out your cucumbers. Check out the following links:
https://extension.umn.edu/diseases/downy-mildew-cucurbits
https://extension.umn.edu/diseases/bacterial-wilt
https://extension.umn.edu/vegetables/growing-cucumbers
https://extension.umn.edu/yard-and-garden-insects/spider-mites
I hope this is helpful,