Hi Sparrow 123,
Tough question! I'm not an expert, just another gardener but I will venture some ideas. Usually a plant will grow out white if grown in almost complete darkness. I'm guessing that is not happening here. I'm guessing maybe that the plant itself looks good and is perfectly green and healthy? Getting plenty of sunlight? And only the fruit, cucumbers are white. Correct?
In that case, if it were happening to me.... Did I buy new seed? I've been buying heirloom seed from a reputable company for many years. Always happy with the results. But the last 2-3 years I've noticed some serious problems with the seed they've sent me. Seems like they have been mixing up the seeds from several varieties. I've recently noticed a few other people with the same complaints about that company so I will use another one for awhile.
I also save a lot of my seeds every year. Some I have saved have been in excellent shape and produce exactly what I want. Happy, healthy plants. Some have not produced so well. Perhaps not the healthiest or best seed to save.
Many years ago I saved cucumber seeds from happy plants that produced well but that must have crossed with other curcurbit plants, possibly gourds or muskmelons I had been growing. The plants/fruits I got did not resemble anything I had ever seen or heard of. Weird stuff. So I am now careful to keep a significant distance between any plants that can cross when I am saving seed.
And my last thought is that your soil is now depleted in something that plant needs. You can look up chlorophyll on the wikipedia page and try to understand it. It gave me a headache. But, if that is the problem... you can amend your soil with lots of compost and/or manure this fall and the problem will probably go away.
I hope this helps. Or perhaps someone with more knowledge will come along to set us straight. Happy gardening.
Debbie
