I've shared some pictures and a video of my melon seedling which have all wilted seemingly overnight...

I've been keeping these seedlings indoors at 75f since germination, but they did spend two hours at 60-65f a couple days ago. Could this have been the cause or is this typical of over watering, under watering, or both? I feel it is not damping off as I lost a few of these to damping off and there was noticeable damage at the base of the stem.

Could this have been caused by leaving a strong vinegar/water solution open on the room overnight? Was doing some deep cleaning and mistakenly left it in there which cause a strong odor. All plants all got similarly wilted overnight which makes me feel like it's something environmental outside which is why I thought I might've gas bombed them with the vinegar vapors, if that's even a thing?

My guess is salt in the air.

SoulReaver009 said:My guess is salt in the air.

I didn't even consider that, but it seems like that wouldn't be a factor given the indoor environment right? I'm keeping windows closed, using a heating unit to keep temp up and a fan.

Thanks for your thoughts!

Even with windows closed, unless you get your air filtered into your house, or have a separate "air system" that provides you with air. There is most likely some salt in the air. More than people who don't live along the coast. I know I can smell the ocean as I get close to it (meaning the salt in the air). Especially being close to the coast. Maybe your nose is used to the smell, so you don't notice it. Maybe your plants will adapt. Someone else who has experience similar to your situation will have to chime in.

I wish I knew of a way that you could test the salt level in the air. And watermelon plants are very finicky about something, I can't remember. I think they don't like the humidity and/or cold. Combined with the salt, maybe that's what it is. Maybe someone can chime in.

It is not salt in the air.
It is likely not from vinegar in the air. It is probably due to the watering schedule and different sized pots.

I sow all my seeds in either the same sized pots like all 3" or all 2 1/2"! Or I use little mini flats. They are 8" X 6" by 3" deep. I use Miracle Grow potting soil. I grow them underlights. 4-5" below the tubes. I raise the lights as the seeds grow.

SoulReaver009 said:Even with windows closed, unless you get your air filtered into your house, or have a separate "air system" that provides you with air. There is most likely some salt in the air. More than people who don't live along the coast. I know I can smell the ocean as I get close to it (meaning the salt in the air). Especially being close to the coast. Maybe your nose is used to the smell, so you don't notice it. Maybe your plants will adapt. Someone else who has experience similar to your situation will have to chime in.

I wish I knew of a way that you could test the salt level in the air. And watermelon plants are very finicky about something, I can't remember. I think they don't like the humidity and/or cold. Combined with the salt, maybe that's what it is. Maybe someone can chime in.

I'm relatively close to the ocean so maybe this is actually a factor...Would've never even considered this! Definitely curious to hear from others in coastal areas about this...

Does the vinegar sound like a long shot to you? I could taste it in the air upon walking into the room this morning, was super strong - my girlfriend is leaning towards this as the cause but don't know if this could even harm plants.

Thanks all for the replies and suggestions!

I'm somewhat of a gardening beginner, so what are the chances of these plants pushing through this mishap, given that the stems are sturdy and the leaves are wilted? The uppermost set of leaves on most plants actually look good, so I'm crossing my fingers.

BigBill said:It is not salt in the air.
It is likely not from vinegar in the air. It is probably due to the watering schedule and different sized pots.

I sow all my seeds in either the same sized pots like all 3" or all 2 1/2"! Or I use little mini flats. They are 8" X 6" by 3" deep. I use Miracle Grow potting soil. I grow them underlights. 4-5" below the tubes. I raise the lights as the seeds grow.

The watering schedule issue may be a factor - they've been unevenly drying out thus I've been spot-watering where it seems to be necessary - probably slightly over-loving them since I'm home all the time during the coronavirus situation.

I've been meaning to pot up the melons in peat pots, but I don't think different sized pots is the factor, since ALL of my melons have exactly the same wilting situation going on - those in larger pots and those in peat pots. And it happened overnight btw.

I don't think it's the vinegar.

However, I was thinking, until bill's post, that the salt in the air is resting on top of the soil, and when you go to water your plants, you flush the salt down into the roots.

Bill says it's not. And to be honest, I would've asked you about your watering routine, if I didn't know where Massachusetts was.

So what is your watering routine like? When and how much?

And wilting and misshapen leaves are not the end!
There is hope. Until the stem where it comes out of the ground turns brown and shrivels. Until all the leaves fall off, and even then, it could come back. Did you notice that it happened, the day after you watered it?

The vinegar if it is that bad might be a much better possibility then salt air.
How far from the water are you? You would need the prevailing winds blowing loadsof humid, salt laden air in through the cracks in your home. I find that hard to fathom. Salt air is not going to sit on the soil surface but it needs to be precipitated out of the air by a heavy dripping fog on fine rain-like mist.
I still say it's watering.

SoulReaver009 said:I don't think it's the vinegar.

However, I was thinking, until bill's post, that the salt in the air is resting on top of the soil, and when you go to water your plants, you flush the salt down into the roots.

Bill says it's not. And to be honest, I would've asked you about your watering routine, if I didn't know where Massachusetts was.

So what is your watering routine like? When and how much?

I'm giving the seedlings a moderate watering (not soaking but uniformly wet) usually once a day.

Re' watering habits, typically, I give an initial widespread watering to all seedling at some point in the morning, whenever most feel dry...meaning maybe a few get watered while they're still a bit moist but most are 90% dry...

Usually, the peat lots dry out quickly and I give another light watering in the evening, but the last few days I noticed that the cups are staying wet longer, with barely one watering per day needed - seems like water intake was slowed a couple days come to think of it...

This lines up with when I transported out of this 75f room for a couple hours...could this have happened from two period in ~60f temp, causing a bit of shock?

I doubt it. I think that a temperature range of 50 and 80 degrees would be okay. Possibly 85.

Right, so probably not temp.

I've also probably ruled out underwatering, since after watering the dry ones this morning, the leaves haven't bounced back at all...and unless these leaves completely died from 18 hours without water I'd expect to have seen a visual improvement by now...

I really have no knowledge on the effects of vinegar in the air. However, I seem to recall people within this forum to say that they sprayed a mixture of water and vinegar to kill and control weeds. Assuming that to be true, it would not be too far off the mark to think that vinegar might have caused this. But who knows?

BigBill said:I really have no knowledge on the effects of vinegar in the air. However, I seem to recall people within this forum to say that they sprayed a mixture of water and vinegar to kill and control weeds. Assuming that to be true, it would not be too far off the mark to think that vinegar might have caused this. But who knows?

Yeah this seems like foreign territory, as googling my vinegar situation returns nothing but yeah I've heard of it's use as a weed killer...yikes

Suppose the next question is do I clip off the wilted leaves? Any harm doing this with a seedling?

I would only clip them, if they are dead. And do not clip the seed leaves (cotyledons).

They are dead if they are dried and crumbly. If they are wilted, I would leave them. They can be your indicator if they get better or get worse. And if they get better then yay! And if they get worse and dry up get and crumbly, then that's more info to you.

If it is caused by vinegar toxicity, chances are the seedlings will die. If it's a watering issue, they will be set back.
I would toss them and sow seeds outside in a week and forget about starting inside.

Thanks for your input everyone...really helped to narrow down possibilities!

If it is vinegar poisoning and they turn out to be done for, guess I at least learned from it.

Happy gardening guys and thanks again!