where are you.. whats the current outdoor weather.. what the greenhouse atmosphere ...

then i wonder.. why you have them in sealed bags.. in a greenhouse??? ...

how hot do the bags get???

could we have a pic of the bags in the greenhouse????

ken

I am in zone 7, just about when spring time starts. Greenhouse is maintained above 60F and up to 80F. Humidity varies depending on the weather since there is on and off rain and sun, but in general, the dehumidifier keeps it below 67% humidity. This does not seem to be due to the environment, since the other cucumber plants in top soil in pots are perfectly healthy, if not slightly smaller.

The grow bags are experimental, and are like the hydroponic grow bags that commercial greenhouses use. The bags don't get very hot as the environment isn't very hot. The bags are for sealing moisture, to test if I can grow cucumbers with reduced watering and if that can help water loss during hot summer days when they wilt everyday.

Your plants could boil in such a bag.

Do some research on Surround ® WP. It's a kaolin clay product, manufactured to mix with water and make a sprayable suspension that coats plants with a film that protects leaves and fruit from scorching sun, water loss, and insect damage.

I've used it for years to protect my tomatoes, cukes, zukes and other squash against all of those issues though I started using it during one very bad Japanese beetle year. I subsequently learned that pros use it for heat and sunburn protection.

Well, its certain the heats not the issue for now. It's still 50F outside. No signs of wilting due to excess heat anyways. Im still trying to figure out the burn type marks and yellowing. They seem to affect only the oldest leaves.