There are several things that can cause yellowing of a cucumber leaf. If the yellow is in spots or patches it is most likely a fungal disease. Your local garden center can suggest an appropriate fungicide if you wish to treat the plants. If the yellowing is primarily on the older leaves, it's probably just a natural thing; oldest leaves are dropped in favor of growing healthy new leaves. If the yellowing is also on the new leaves, try fertilizing with a little nitrogen. Thanks for the question. Please stop in again soon! |