Seedlings dampening off & humidity, WWYD?

It's been too long since I've had seeds and I'm seriously screwing it up. Bear with me, I've been growing only a few years but mostly with cuttings as seeds are hard to come by here. I left humidity domes on and I've lost one of my precious seedlings to fungal attack. Domes are off now and I'm giving everything a chance to dry out. I'm using a coco/commercial soil/perlite mix that I thought was sterile, but clearly it wasn't. The seedling to die was the last to pop, about a day later than the others, so it might have been afflicted from the beginning.

Temp is spot on and pretty stable with lights on at 25°C. Lights are not overpowered; three 30W Phillips household LEDs in a cloning box I made. Because the lights don't put out much heat (and we're coming into winter) I have a propagation heat mat to keep the temp up. I have a computer case fan running that's more than capable of replacing the air volume of the cabinet every minute, but since the dampening off I've been using an extra fan to get more air circulation.

Humidity is now hovering between 45-50%. I know this is generally much too low for seedlings, but I'm terrified of the fungus returning. Thoughts?

No domes
No overthinking
Don't reuse any suspect medium
Drop seeds into wet medium and wait without disturbing them

The heat mat isn't necessary unless ambient temp is below 68f
Usually stretchy seedlings is due to inadequate lighting
Humidity is fine
You can do it

Ditch the dome.......not needed for seedlings.

domes are great for cuttings to keep the humidity up and help them root, but as has been stated above, just get some potting compostand damp it up, well i use flower pots so i put somesoil into the pots, useing the bottom of a pot of the same size to push the soil down and place them into a washing up bowl with some water in it and wait for the compost to become wet as it draws the moisture up through the soil . take them out to drain any excess water off. then dic a small hole about 1cm deep and put the seed into it, cover it over with the compost and leave it to germinate someware that isnt cold, but not too hot. then if the soil dries a little, i dip my fingers into some water and let it drip onto the area above the seed, that way you dont over water them and within a few days the seed pops it little haed out. then its strait under a light

seems to help me to pick a format and stick with it. then just change little things until learning what works best and what it should look like. meaning change things like amount and schedule of water, depth of seed, light type while keeping basics the same like container type, media, heat, dome...etc.

Thanks everyone for advice, obviously I'll be doing things differently in future. The issue is that these are some pretty special seeds and we're not legal here so they're damn hard to get. I really want to save this grow if I can because I don't know that I'll get a 'next time' with these genetics.

Herb & Suds said:

The heat mat isn't necessary unless ambient temp is below 68f
Usually stretchy seedlings is due to inadequate lighting
Humidity is fine
You can do it

Click to expand...

TY for this!

So humidity in the 45-50% range won't harm the seedlings? And should help stop any further losses to fungus with any luck? If it's not too late that is.

DankDeeds said:

Thanks everyone for advice, obviously I'll be doing things differently in future. The issue is that these are some pretty special seeds and we're not legal here so they're damn hard to get. I really want to save this grow if I can because I don't know that I'll get a 'next time' with these genetics.



TY for this!

So humidity in the 45-50% range won't harm the seedlings? And should help stop any further losses to fungus with any luck? If it's not too late that is.

Click to expand...

Seeds sprout just fine at lower humidity in nature. It's a hardy plants. Just don't drown it by giving it to much water. Tilt and water along the edges of the pot and never directly on the stem.

Keep a fan blowing across the soil surface, it will help sort most problems with damp off/wilt. It's the anaerobic environment that causes wilt of, low air flow and to much water. Good luck! You can do it!

Wastei said:

Seeds sprout just fine at lower humidity in nature. It's a hardy plants. Just don't drown it by giving it to much water. Tilt and water along the edges of the pot and never directly on the stem.

Keep a fan blowing across the soil surface, it will help sort most problems with damp off/wilt. It's the anaerobic environment that causes wilt of, low air flow and to much water. Good luck! You can do it!

Click to expand...

Thanks! I'd just moved my fan closer so fingers crossed it helps. Thanks for the advice re watering; I'll give that a go. I know these things intellectually, but my anxiety gets the better of me & I tend to kill things with 'love'.