Seedlings stage I’m failing badly

So my success rate with seedlings is horrible
I get them to pop
They make it a couple of days
Stretch hard then wither and die typically in the first 5-7 days
I’ve burned through a lot of seeds and I can’t figure out what I’m doing wrong
I had 3 that survived out of 5 on my first run
That’s about ready to come out of the tent and I’m trying to have 4 ready to go when these come out but I can’t seem to keep them alive
Temperature is in the 70’s
Humidity is running high but falls off pretty hard if I don’t water
I had read to never let them dry out and I didn’t the first round
I’m seeing a lot of people saying not to over water seeds though
So basically how much water should they be getting
I’m using a 50/50 mix of happy frog and 70/30 coco


Too wet. Almost guaranteed. That propogator should be doing well. Less water. The propogator keeps humidity high. They pull water from the air as they build roots. Very little water needed in soil in that system. Use half or less water. Start with moist soil. Dont water till you just have to. I also use a propogator. If they stretch fill in around the stem.


Agree with @Storm. Do you have holes or slits cut in the bottom of those solo cups? I would raise those cups also to help with the stretch, you can have those seedlings 2” away from the light under those low wattage lights. Nice rig for seedlings :muscle::muscle::love_you_gesture:


Looks like the Growmies @Storm @OGIncognito have got you covered!! Find your sweet spot for your light and less is more when it comes to water. This last round I’ve also dug my hole a little bit deeper and bury the stem up to it’s neck in perlite to help with holding it up if it stretched too much and stem rot. So far it’s been working well with that method.

In case anybody was wondering that’s sphagnum moss on top to hold moisture in the soil.


Thank you all for the advice
I’ll try and implement these
Really love this forum for this very reason I can come here and just get help without anyone ripping me down
Yes I have 1/2” holes drilled into the bottom of the cups
I don’t really have a way to raise the cups though
I have a new system coming but it will probably be next week before it’s here
This was a cheap $15 dollar set I found on Amazon I added the heat mat because it was staying way too cool in here
I have to keep the a/c cranking or my tent gets really hot like 90°+
The new system I have coming is supposed to have a tray in the bottom for raising them
In the meantime I’ll add more dirt to the one that’s stretching
Neither of them are doing well
I’ll back the water way off
FYI because of the a/c running so much the humidity in this room stays very low like 40’s low


Put a puck or wadded up paper towel or something under the cups to raise them. You have a nice setup. I used that same one then went to 5” pots or seedlings and put a clear solo cup over them. Happy Frog is good soil and I also used it with fox farm ocean forest 50/50. Now I grow hydroponic which seems to be less problems for me with pest and watering issues. Good luck, this community is very experienced and always helpful


I personally don’t mix coco and soil. It’s a recipe for disaster! The two pH’s fight each other.

Also, the second the seed pops the dirt I get rid of the dome lid. They need AIR. However, you say your room is 40% rh and that’s way to low for seedling. I keep my seedlings around 80%

Work on the humidifier. Your gonna need it

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Switch the lights to nights. Heat of the day off. As long as can keep dark. Helps temps a lot.


Others with more knowledge and experience already tapped in, but I will offer my routine. Been a while since I used solo cups, I use plugs now with a 2 oz paper pot. I drop an oz of water on them when I tuck the seed in and when they dry out I an oz or two of water in the tray bottom next to the pot and allow them to wick up. The paper isn’t as tall as the solo cup, so the plugs get enough moisture for the seed zone to be damp, but they don’t wind up swimming in water.

I check em in the morning and after dinner, the excess water in the tray converts to humidity to feed the leaves.

The only time they did not catch was this last batch, only sprouted 4 out of 5, but I think that may have been a ph issue that I skipped over. (Used tap water and didn’t ph it down from 7.6). Or the 8 year old seeds I gave a go, they didn’t crack… getting a leg up after to many years happens to be a challenge for plants to I guess😂.


That’s the first I’ve tried it with the coco
I keep the vents open
Is that still not enough air

Do you have a humidifier to get your humidity up?

Yes and 40% humidity is the room not the tent or the prop
The tent I’m in late flower and keep around 60ish
The prop stays high varies a lot but mid 60’s is the lowest I’ve had it
You really got me thinking on airflow
I definitely smothered a batch when I sealed my tent up air tight and didn’t have the ventilation fan set up correctly

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I thought your problem was you didn’t have a humidifier. I would lose that dome. They don’t need it they need air. Like I said, the second the seed pops out I take the dome off. (That’s me)

If I take the dome off then they’re sitting in a very cool room 65-70° with a 40-50% humidity
I cannot run the humidifier in the entire room for multiple reasons
This is the only space I have available and the legality of growing outdoors is very sketchy in my state

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Really cant get much better. Spring weather numbers. Humidity in range. You have 7 degrees upwards temp play and still in a great cannabis range. As the veg gets going I would get my temps high 70s. Just my thoughts.

Okay as of right now I have 63° and 42% humidity in the room
Here’s the trick my tent has 3 ladies inside that are in their last few weeks of flower I’m thinking 2 more weeks at the longest they are on their night cycle and it’s 68° with 57% humidity
If the temperature in the “lung room”
Idk if that’s the right term lol
Goes up even a little bit then the temperature humidity and vpd skyrockets in the tent
I will definitely try switching those out of the dome in the future as of right now everything in the propagator died only 2 seeds popped and the seedlings wilted and dried out to nothing from last night to today
So I gotta buy more seeds and start over

Are modern genetics so frail because of them being feminized
I mean we’re talking 20 years ago I used to throw them in 5 gallon buckets in a closet in my basement and never had problems until flower and find out they were all male
I didn’t do anything with them except throw a bit of miracle grow at them one time after they got about 8 inches tall wouldn’t have even known what anyone was talking about if you said ph
I never had issues with anything dying
It was always just that maybe 1 out of 5 would actually be female and I would always realize it late so I would have a seedy harvest
Never had a problem growing seeds give them a crush test soak em in water usually just a couple hours then throw them in a bucket of generic top soil
This is all so much more complicated nowadays