What's wrong with my Cucumber Plant?

[findingmulberry]

Hello! I can't figure out what is wrong with my cucumber plant.





I thought it might be something like powdery mildew, but it's not on the surface of the leaves. Rather, the green surface of the leaves seems to be "disappearing" and this white layer underneath is being "exposed." Any idea what it is?

[hendi_alex]

Looks like a very tender plant that has been exposed to overly vigorous sunlight, wind, rain, or all three. The damage is not permanent. Just be sure to gradually harden the plants off before moving them outside.

You can see that the green has literally been rubbed off of the plant, leaving just the base membrane. The hardening process, which occurs naturally when plants sprout and grow outside, causes tougher cells to develop over the leaves. You will notice that leaves forming outside do not have nearly the delicate look as these pampered indoor plant leaves.

[imafan26]

I thought the leaves might be chloritic from being exposed to excessive indoor lighting. It is a common problem of winter grown greenhouse cucumbers grown under continuous light.

[hendi_alex]

That sounds like an excellent possibility, especially if the plants haven't been taken outside. The damage seems limited to just the upper leaves. If over exposure outside was the problem, it would seem that the other leaves would have been affected as well.

Still just a temporary problem, and no permanent damage!

[hendi_alex]

BTW, your cucumbers are way ahead of mine, but I did notice that mine are popping up. They are planted in 1 gal. nursery containers and are outside in portable cold frames. Can't wait for those first early cucumbers!

[findingmulberry]

Wow! Thanks!

I'm guessing it must have been the sun. I got the plant from a nursery last week and only a few days later, left it in the harsh afternoon sun.


The weather here has been crazy. Since mid-January, it would warm up to the 60s-70s for a week then randomly drop into the 30s. Avg last frost date used to be mid-Feb, and now it looks like it's late-March .

I planted my first batch of seedlings a month ago expecting to be able to move them outdoors for sufficient light, but the wacky weather made it impossible. (No indoor lighting system and the sunlight wasn't coming through the windows yet). I'm almost done hardening off the seedlings that survived the ordeal. Lost all of my Thai Hairy Lemon Basil, almost all of my Cosmonaut Volkovs, and a couple of the others, both to lack of light and dropping accidents.

The survivors are very behind in their growth, but most of them are responding very well to the outdoor sunlight.

The month-old Costoluto Genovese just sprouted their first true sets of leaves a few days ago.

My tiny strawberry seedlings are still teeny tiny, but upon closer look, they too are sprouting true leaves.

Basil... not so much. The month-old basil seedlings still look like they just sprouted a few days ago.


I have another batch going, and the newer seedlings are doing much better. Going to sow artichoke and the Cosmonauts again soon.

[applestar]

Cosmonaut Volcov -- tomato right? I've been teadfastly refusing to look this one up, but just now finally broke down and looked it up.

...I will NOT start another tomato seed (well, except for Black Cherry)...

But I did add it to my 2014 Wishlist.
Have you grown it before? Do you know if the vines grow big or stay somewhat small?

You cucumbers look like the new leaves are fine, so hopefully they will recover.... If there IS any chance of fungal infection, I would spray with milk solution -- especially those damaged, weakened leaves -- as preventive.

[findingmulberry]

Yup! It's supposedly a very good, drought-resistant tomato... at least from all the reviews I could find.

It's my first go with growing plants, so I'll let you know how the Cosmonaut goes in a few months if it makes it.