Compost the cuke. Sorry, its just tough love.

Start from seed no more than 2 weeks before May 20th-June 1st or simply direct seed outside on May 20th.

Here is the problem with getting an early start on cucurbits:

Once they reach the 3rd true leaf stage they go crazy with both above and below ground growth. If they are transplanted into warm soil at the early 3 leaf stage they do great, but waiting any longer compromises their long term performance. The above ground growth will be fine, but their below ground growth will be stunted by the seed starting container and once this occurs there is no full recovery possible. This is why many regard cucurbits as poor transplants. They are fine to transplant if it is done by the early 3 leaf stage, otherwise they suffer.

Starting cucurbits early does not benefit them due to the insane root growth they try to do after the 3rd leaf stage. Your present plants simply will not do well if you keep them. They are already stressed out and are sending chemical signatures to all the cucumber beetles and squash bugs to come and dine.

Start over by indoor seeding between May 6-13th and transplant as soon as the 3rd set of true leafs just emerge or direct seed after May 20th and you will get much better performance.

Drat. Thanks again, Justaguy.

I started some too! I've been letting them spend the day in the greenhouse, then bringing them in at night. I even forgot them out there one night and they made it through (probably about 35-40 degrees). I'll plant them and see how they do, but I guess I better start a few new ones too. I was so excited because they looked so good! I'm as bad as you are, SO impatient! :)

Oh well, thanks justaguy. Every year I learn something new!