The seed leaves do always die back as soon as the food reserves in them have been used up and the plant has true leaves that are photosynthesiing. If the plant looks otherwise healthy I wouldnt be concerned.

My main concern with your melon would be that it likely hasnt been hardened off yet. If it hasnt and you have it in full sun thats a no no. If you could post some pics it would be helpful to advise you further.

Same with your maters. They need to be gradually adjusted to life in the big bad world before you just throw them out in it. I would start doing it now and then you should be able to plant them out between next weekend and the middle of next week. Forecast for Denver is lows not far below 50 for a good while. Mid 40s wont hurt them once they have been propely adjusted.

Lots of people pinch off flowers until about 2 weeks after putting them in the ground anyways so losing your flowers now isnt a big deal.

Here is a pic of the Ambrosia melons. I decided to give them a good drink after this pic since they looked thirsty to me. My balcony is my only growing area right now, so they won't be planted out so to speak. I will be hardening them off to live on the balcony. I know melons do best in the ground, but it's not an option right now for me.

Thanks for the info about the seed leaves. I knew I wasn't crazy lol. Good thing to know since it will probably happen to most plants... no good to worry over every seed leaf lol.

The balcony itself doesn't get direct afternoon sun, but does have direct morning sunlight. What I've been doing for the melons is the same I've done for the tomatoes thus far, letting them sleep inside and setting them out in the shaded balcony in the afternoons. Is that good?

The tomatoes, other than the one I just got, have been hardened off and were living outside until I thought it was too cold for them at night. I may just start leaving the hardened off one out overnight again. Do you think they need re-hardened off?

How long do you have to harden them off before you can fully trust it? Thanks!

I would put only one melon in a pot that size, even then, you may me disappointed. I would go for 5 gallons per plant minimum, and that's a very liberal low ball. They are greedy little buggers and have extensive roots systems.

I know that growing on a balcony isn't optimal, and we have to work with what we have (in my case its sun-blocking trees, and being gone for 2 weeks next month) but growing melons in that tight space is going to be a tricky affair. They need room, lots of it. You can skirt this issue some by growing them up a trellis. If you haven't already, you can look into that option to save space.

Otherwise they look pretty darn healthy! If it were me, I wouldn't worry about the seed leaf on those unless you start noticing the other leaves starting to go south.

I have been bringing in my winter squash every night, and probably wont plant them out until next weekend. high 40's probably wont kill them, but, all they are going to do if I plant them out now is sulk and complain at me until it warms up consistently. So yes, you've been doing the right thing as far as I'm concerned.

What you will want to start doing, with both tomatoes and the melons, is exposing them to the morning sunlight a little at a time. Also, with the tomatoes, exposing them to some cooler temps, too, that way you can start just leaving them outside all night.

However, for your tomatoes that have already been hardened, it depends on how long you've "reversed" hardened them. If it's only been a day or two, I wouldn't worry too much. It happens to me all the time since I have drill every month and can't come home to move plants in and out so they usually wind up staying in for 2 days until they get to go back out. Mostly my tomatoes do okay. Some other stuff it seems to be a little rougher on.

My hardening off method is very unorthodox. It is haphazard and sloppy but I am a lazy gardener and have 10,000 other things going on in my life. I can't, and wont, spend hours moving plants in and out of sun, in and out of the house. I have been hardening my tomatoes for about 3 weeks now but mostly because I couldn't trust the weather enough to plant (after last weekend I'm sure glad I waited). For me, usually after about a week-10 days they are ready, depending on how long they've spent inside (bell peppers seem to take the loooooongest time to harden off for me, but that's due to the fact I start them at the end of February and my awful hardening off method).

Hope that all helps, if you have any other questions or need me to clarify, I'm here to help! Also, hopefully some other folks can get in here and tell you all the points I'm wrong on. There's a lot of folks here that are way more experienced then me and would probably be able to help you more!

Thanks Zach, as a newb gardener, and container gardener at that, I lack confidence at times lol. So I come here for reassurance!! But mostly I come for the advice and knowledge hehe.

I like that you confessed to your wild hardening off methods, as mine as also less orthodox than what others might suggest... I'm a night owl lol and I rarely see the morning sun myself, so exposing the plants to morning sun is harder. It entails me putting them back out before sunrise and then leaving them out for the hours I sleep, and basically hoping they will be okay lol.

Call me crazy, but would that sort of setup work for like stage 2 of hardening off? Like the first week, set them out in the shaded afternoon until it gets dark, and bring them back in. Then week two begin leaving them out as I sleep my crazy hours?? Or will that do more harm than good by confusing the crap out of them?

One more thing.... How do you think they would do if I replanted 2 or 3 of the melons into a large recycling tub? It's about the size of one of those plastic storage tubs that go on sale at walmart during the holidays. It also has hole already in the bottom. I just don't have many containers of at least 5 gallons right now or means to buy anymore.

Should I go ahead and replant now? Or give a week resting period? I don't want to over stress them. Thanks so much for your responses!

Oh, I don't have even half the experience as some of the folks on here, but I can grow a crop lol. I am not great at container gardening, but I keep trying every year because I always grow way more than I have space for!

As long as the switch is somewhat gradual, it should be okay. Like I said, my way is pretty haphazard and I'm sure stresses and confuses them more then necessary, but, they seem to live through it.

Depends on how big the recycling tub is... I'm thinking of the one I have that I just planted a tomato in (I think it holds about 2 cubic feet of dirt), and I would only do one. The more space you can give them, the happier they will be. Over crowding them, in my opinion, will result in fewer melons than having one happy plant.

digging up and transplanting melons (cucurbits) isn't easy, either. I have done it with cucumbers and summer squash, but, they really don't appreciate it.

In your case, I think your best bet is to let them grow and have the root ball fill out the container they are already in then transplanting the whole shebang into a larger container, then, and it's going to kill you, thin them.

OR

Try to separate those three and see what happens. If I listened to everything I was told and read, I wouldn't have any of the knowledge and experience I do now! Gardening is often about finding what works for you. Tinkering, experimenting, failing, and, every once in a while, succeeding.