Symptoms of Overwatering and Underwatering in Seedlings

Hey, I have been reading a lot of books on growing but none of them dedicate much time to seedlings. I also used the search function but couldn't find a thread about over/underwatering in seedlings in particular.

Can someone tell me the symptoms of overwatering and the symptoms of underwatering in seedlings?

Thanks. Please describe the symptoms in as much detail as possible because I am a total newbie and really need help with my seedlings.

It is pretty much the same as for larger plants, except seedlings are more liable to suffer permanent damage/death or, the case of over-watering, a fungal disease (damping off, root rot). A little seedling that is severely under watered will go limp and begin to wilt, soon enough it will simply shrivel up and flop over.

An over-watered plant wont go completely limp as if it is dead, rather the leaves will sag and curl inward/under. It is at increased risk of developing a root infection or damping off.

A seedling that is only mildly under-watered wont grow as vigorously; it wont be absorbing nutrients to full capacity.

Best course of action is to water your seedlings thoroughly, until you see water (run-off) drip from the bottom of the container. You wait roughly a couple days, when the soil surface has dried out some (not TOTALLY) you do it all over again. If the soil was near completely dried out when you watered then it is just going to piss right through the container, don't wait that long.

Thanks man. Some of my seedlings have a leaf curled under, and also a lot of them have the seedling leaves growing really long(often one longer than the other). I understand the curling under is an overwatering issue, but what about the weird growth of the seedling leaves? One of them is totally asymmetrical with one seedling leaf twice as long as the other. What is causing this?

Also, two of them have a small yellow dot on the seedling leaves. Its on the same place on both sides, and hasn't gotten bigger or smaller for days.

Mostly I am worried about how long the seedling leaves are getting and how asymmetrical some of them are.

All you want to do is keep your soil moist in the seedling stage. You also want to make sure you keep your light as close as you can to the plant without burning it. I wouldn't worry too much about the leaf sizes at this stage. Once they get a little more mature it will be easier to diagnose any problems.

Yeah man, I know the goal is just to keep the soil moist but I'm totally new at this and I don't really know how moist is right. I've been lightly misting the top of the soil daily up until two days ago when I found out the leaves curling under was a sign of overwatering.

So can anyone help me out with the symptoms of overwatering and underwatering? How should I water(should I keep using the spray bottle or should I actually pour water in there)? How do I know when its time to water?

I need to know how I can know when its time to water the seedlings. Everyone always says stick your finger in there and see if its too dry, but I don't know the right amount of moisture so I need a little more detail than that.

And the leaves are totally asymmetrical. Why would one be twice as big as the other one?

Thank you. I'm sorry if these are stupid questions.

Some photos would help us to help you out, if possible to post some. But as for leaf weirdness, it is not uncommon for babies to start out a little odd looking. They usually get theirselves together in another leaf set or two - but sometimes you get a plant that just wants to ride the short bus! Let them do their thing and see what happens...

As for watering, its better to water until you get some runoff (you did remember drain holes, right) and then let it be until the soil dries out again. You can kinda tell when by the weight of the cup/pot you have it in. Get a feel for its weight when you've got it fully watered, then monitor that and water again when it feels much lighter and looks dry.