Cucumber and Summer Squash plants turning yellow

Asked June 2, 2015, 9:40 AM EDT

I have cucumber and summer squash planted in a hoop house, why are the plants turning yellow?

Luce County Michigan

1 Response

There could be a number of reasons why your cucumbers and squash leaves are turning yellow. It's difficult to really diagnose the potential problem without more description or a picture of the actual plants that shows if they are entirely yellow or are the young parts yellow or are there yellow spots? Some causes of yellowing could be from a nutrient that is lacking or perhaps, unavailable to the plant due to a pH that is too low or too high. If you haven't had your soil tested within 3 years, this is always a good start; it will tell you what is present in your soil and what is recommended to help your plants grow successfully. You can visit to request a soil test kit or contact your local Extension office. Be sure your plants are receiving at least one inch of water per week at their base. Of course, cucumbers also require at least 8 hours of full sun to effectively produce fruit. Overhead watering causes potential diseases. Again, depending upon the symptoms of the yellowing, if there are spots, this may also be caused by an insect. If you have already ruled out any of the above suggestions and feel that's it's somehing else, you can upload some pictures relating to this question; and this may help in further identifying the issue.