Without seeing a photo it's hard to know exactly what the issue is, Carolyn, but I suspect you have a case of powdery mildew, which is fairly common on cucumbers. Depending on how significant the problem is, you might start by spraying the leaves with baking soda (1 teaspoon in 1 quart water), which will raise the pH, creating an inhospitable environment for powdery mildew. If the condition worsens, you may have to resort to a fungicide. You'll find more from University of Illinois Extension here:
I think this is something I would try, thanks , any suggestions for fungicide? I have always been afraid of fungicide. I will save that website from U of I extension..Thanks a lot
I am beginning to combat this for the first time, on my peas and mint (and potentially beans). I did the baking soda last night and this morning, and it seems to have helped. but given how much there is (and how fast it came on), I saw on the UC Berkeley site that horticultural oil is the best thing to get rid of it. So I have some coming from Amazon, but meantime, baking soda seems like it will at least keep it from getting worse.
Carolyn, Safer makes an organic fungicide. I would use any of their products with confidence.
Nancy, make sure you check the label on your horticultural oil for temperature restrictions before applying.
Thank you. Right now I am trying the baking soda and water...I will get some epson salts to have on hand in case I need it.
R. Adam Q....what are the proportions of epson salt and asprin...say for a quart of water.?