Help please...Seedlings have stopped growing

[Keith Tyrion]

Hi All

My seedlings have stopped growing after two weeks, are turning pale green and bending over. I'd be very grateful for any advice as to why they aren't flourishing.

1) PICTURE OF PLANT Below
2) Growing indoors - 100w LED at 30cm hang height.
3) Watering schedule - Approx every 3-4 days.
4) Growing Medium - Osmocote Seed Raising/Cutting Mix
5) What stage of growth - 2 weeks

Temps and Humidity are in one of the attached photos..

Many thanks for your help!

Keith

 

[Kushash]

Hi All

My seedlings have stopped growing after two weeks, are turning pale green and bending over. I'd be very grateful for any advice as to why they aren't flourishing.

1) PICTURE OF PLANT Below
2) Growing indoors - 100w LED at 30cm hang height.
3) Watering schedule - Approx every 3-4 days.
4) Growing Medium - Osmocote Seed Raising/Cutting Mix
5) What stage of growth - 2 weeks

Temps and Humidity are in one of the attached photos..

Many thanks for your help!

KeithView attachment 4155066 View attachment 4155067

Could be one or more of these things.
1) 16c is a bit cold. Lifting the pots off of the floor might help.
2) Not familiar with the medium but visually it might not be a good choice IDK.
3) Not enough light. Is 100w the true wattage of the light or is that what the company is saying it is rated? It would be best to give us the make and model of your light to make sure it is 100w. ​

 

[Ringsixty]

I think,over saturation of water. That product contains water retaining wetting agent.
I experimented with soil containing wetting agents. Not good
Picture 1 is of 2 plant in a similar soil product. Slow growth and unhealthy plants.
Pulled the plants after 1 month. Knock of the soil and transplanted into Fabric pots with some cheap Supersoil with 30% Perlite mixed in
Picture 2 is the end result.

The plant's need to breath.

More light is needed

Good luck

 

[Tim1987]

Hi Keith.

Ill just tell you what i see in a list -

Your pots are too big.
Your soil is too wet. Overwatered. Seedling mixes tend to hold a lot of moisture. A large pot will only amplify this. I can see the soil is very damp further down.
Wet soil combined with low humidity isnt good at all for seedlings.
They're quite stretchy like they need more light. But dont seem to like the spectrum either. Could you please explain your light a little more. Brand, true wattage, type of led etc.

I dont often recommend it. But given their size, and problems, it may be best to transplant into something better, in a smaller pot.

A bit more information is needed. If you dont know the answers to a couple, thats cool. Just say so.

Soil ph?
Have you fed any nutrients since sprouting? Anything at all.
Water source? If its tap water, what the ppm?
How consistent are those cool temps and low humidity?
Any heating, or environmental control? Thermostats etc.
What type of 100watt LED?
Were the seedlings at any point green? If so for how long? Did anything change all of a sudden? Such as nutrient, light, temperature, humidty etc. Any coincidences?

Good luck.

Tim.

 

[Roger A. Shrubber]

32% rh is pretty low, it would be better to get that a little higher and water a little less, and 32C is 90F, that's pretty warm, especially at 32% rh, any way you could drop that down to about 28?
i'd also water just around the base of your plants for now, looks like they need some more time to grow some roots before you start watering the whole pot

 

[Keith Tyrion]

Thank you all for the quick feedback - much appreciated.

@tim - Soil ph? Not sure.
Have you fed any nutrients since sprouting? Anything at all. I hadn't when I took that photo, only tap water - but before i saw your feedback this morning I gave some 1/2 strength 5/1 liquid feed (15ml per plant).
Water source? If its tap water, what the ppm? Tap water
How consistent are those cool temps and low humidity? Pretty consistent - exhaust rigged to thermostat (i.e. when it hits 29C the exhaust kicks in - the ideal temp is set at 24C with +/- 5C - i can change that if needed)
Any heating, or environmental control? Thermostats etc. As above
What type of 100watt LED? Ursa Helios GT 100W (more below)
Were the seedlings at any point green? If so for how long? Did anything change all of a sudden? Such as nutrient, light, temperature, humidty etc. Any coincidences? No major changes - seeds not green.

I will try new soil for sure and try to get the temps down a bit.

The light is 1 X Ursa Helios GT 100W Full-Spectrum Cool - 5000K - I would be very interested in your thoughts on this as I cant find much online in terms of seedlings. Grow space is 0.6M (Deep) x 0.5m (Wide) x 1.4M (H).

Thanks again for your help.

Keith

 

[Tim1987]

Thank you all for the quick feedback - much appreciated.

@tim - Soil ph? Not sure.
Have you fed any nutrients since sprouting? Anything at all. I hadn't when I took that photo, only tap water - but before i saw your feedback this morning I gave some 1/2 strength 5/1 liquid feed (15ml per plant).
Water source? If its tap water, what the ppm? Tap water
How consistent are those cool temps and low humidity? Pretty consistent - exhaust rigged to thermostat (i.e. when it hits 29C the exhaust kicks in - the ideal temp is set at 24C with +/- 5C - i can change that if needed)
Any heating, or environmental control? Thermostats etc. As above
What type of 100watt LED? Ursa Helios GT 100W (more below)
Were the seedlings at any point green? If so for how long? Did anything change all of a sudden? Such as nutrient, light, temperature, humidty etc. Any coincidences? No major changes - seeds not green.

I will try new soil for sure and try to get the temps down a bit.

The light is 1 X Ursa Helios GT 100W Full-Spectrum Cool - 5000K - I would be very interested in your thoughts on this as I cant find much online in terms of seedlings. Grow space is 0.6M (Deep) x 0.5m (Wide) x 1.4M (H).

Thanks again for your help.

Keith

Yeah. I think transplanting into something smaller is a good idea.
They didnt need that nutrient either. Wont do them any good at all.
I think even use the seedling mix. But add some perlite, or something similar. More aeration is definitely needed.
Water only.
Leave any rich soil, or nutrition for later, when they've recovered and need a bigger pot.

24'C is pretty good. Dropping to about 20 during lights off is generally a good idea too.

Imo that 5000k lighting is a bad spectrum for seedlings. Intense sun is between 5-7000k in mid summer.
Seedlings like something more red. Something gentle. 5000k is too intense for a seedling.
Something around 2800k to 3500k would be a lot better. You will need more light too. But its the spectrum right now thats a problem.

The large pot and wet soil isnt helping at all either.

Im gonna go with wet soil, and wrong light spectrum, thats the major cause of what you're experiencing.

Good luck OP

 

[whitebb2727]

Yeah. I think transplanting into something smaller is a good idea.
They didnt need that nutrient either. Wont do them any good at all.
I think even use the seedling mix. But add some perlite, or something similar. More aeration is definitely needed.
Water only.
Leave any rich soil, or nutrition for later, when they've recovered and need a bigger pot.

24'C is pretty good. Dropping to about 20 during lights off is generally a good idea too.

Imo that 5000k lighting is a bad spectrum for seedlings. Intense sun is between 5-7000k in mid summer.
Seedlings like something more red. Something gentle. 5000k is too intense for a seedling.
Something around 2800k to 3500k would be a lot better. You will need more light too. But its the spectrum right now thats a problem.

The large pot and wet soil isnt helping at all either.

Im gonna go with wet soil, and wrong light spectrum, thats the major cause of what you're experiencing.

Good luck OP

Nah. 5000k is fine. That's not doing it.


I suspect temps and over watering.

 

[JohnDee]

Hi Keith,
I have two observations...both of which argue toward transplanting into better medium.
#1 The medium has time released nutrients in it. Always a bad idea because you lose control...
#2 That medium is coir based. One persistent issue with coco coir is the possibility of high NaCl content (stuff is matured on the beach)

And regarding #2 salt in coco...the end result is that the seedlings stop growing...just like yours did. Stalled. stunted...whatever the word...seedlings do not like salt.
JD

 

[bankheadstoner]

Thank you all for the quick feedback - much appreciated.

@tim - Soil ph? Not sure.
Have you fed any nutrients since sprouting? Anything at all. I hadn't when I took that photo, only tap water - but before i saw your feedback this morning I gave some 1/2 strength 5/1 liquid feed (15ml per plant).
Water source? If its tap water, what the ppm? Tap water
How consistent are those cool temps and low humidity? Pretty consistent - exhaust rigged to thermostat (i.e. when it hits 29C the exhaust kicks in - the ideal temp is set at 24C with +/- 5C - i can change that if needed)
Any heating, or environmental control? Thermostats etc. As above
What type of 100watt LED? Ursa Helios GT 100W (more below)
Were the seedlings at any point green? If so for how long? Did anything change all of a sudden? Such as nutrient, light, temperature, humidty etc. Any coincidences? No major changes - seeds not green.

I will try new soil for sure and try to get the temps down a bit.

The light is 1 X Ursa Helios GT 100W Full-Spectrum Cool - 5000K - I would be very interested in your thoughts on this as I cant find much online in terms of seedlings. Grow space is 0.6M (Deep) x 0.5m (Wide) x 1.4M (H).

Thanks again for your help.

Keith

The soil looks terrible. But let's talk about a few things you need to do
1 . Get that soil dry as fast as possible . One way is to set it outside or in a window seal for a few days . If that's not a option then poke a few wholes in the soil around roots it'll help get some oxygen to roots . Or just transplant but you would have done that already if you could so do the window seal method but tonight you can poke some wholes
2. Sounds like you not measuring your pH if your not I highly advise you get a pH meter if this is the case
Tip: tomorrow go to a dollar store or rite aid and buy some Solo cups and then transplant them but if you don't have any more soil then use the same soil but make sure you keep the soil loose and don't compact it because it's wet and will not help roots breathe but if soil is loose it dries faster than compacted soil
Just trying to help you with tips you can do right now if you can't get new soil or pots

 

[Tim1987]

Nah. 5000k is fine. That's not doing it.


I suspect temps and over watering.

Like i say definitely damp soil is the problem, and pots too big.

All the little things add up. A wet medium with a 5000k spectrum would not help at all imo. Isnt metal halide and t5 between 3500 - 4000k?
I respectfully disagree.
My viparspectra did exactly what you see if it was on veg. Just saying. Its exactly the reason i asked about the spectrum.

Main problem is soggy media, and too large container without adequate aeration.
The light is just tagging along for the ride.

Red spectrum is without a doubt better for seedlings. It emulates early spring etc. They prefer it.

Needs a smaller pot.
Needs a better propagation mix.
Needs more aeration.
Needs to know the ph.
Needs to know the water quality. Could be 500ppm for all we know.

If OP has a softer light in the meantime. It really wont hurt. It may even be better.

According to OP's last post the temps are 24'C on a thermostat. Temps shouldnt be a concern right now.

 

[whitebb2727]

Like i say definitely damp soil is the problem, and pots too big.

All the little things add up. A wet medium with a 5000k spectrum would not help at all imo. Isnt metal halide and t5 between 3500 - 4000k?
I respectfully disagree.
My viparspectra did exactly what you see if it was on veg. Just saying. Its exactly the reason i asked about the spectrum.

Main problem is soggy media, and too large container without adequate aeration.
The light is just tagging along for the ride.

Red spectrum is without a doubt better for seedlings. It emulates early spring etc. They prefer it.

Needs a smaller pot.
Needs a better propagation mix.
Needs more aeration.
Needs to know the ph.
Needs to know the water quality. Could be 500ppm for all we know.

If OP has a softer light in the meantime. It really wont hurt. It may even be better.

According to OP's last post the temps are 24'C on a thermostat. Temps shouldnt be a concern right now imo.

Nope. Spectrum has no part in it. The spectrum isn't too intesne. Only the size or distance of the light can be unless it's in the uv range.

5000k is actually about perfect for growing. It's the closet to natural daylight.

Ive grown with various lights from cfl, t5 and led and a number of them were 5,000k.

I've also grown from start to finish will all 2700, 4000, 5000 and 6500k each at one point or another.

I can say with 100% certainty that it is not spectrum.

Mainly the moisture.

 

[Tim1987]

Nope. Spectrum has no part in it. The spectrum isn't too intesne. Only the size or distance of the light can be unless it's in the uv range.

5000k is actually about perfect for growing. It's the closet to natural daylight.

Ive grown with various lights from cfl, t5 and led and a number of them were 5,000k.

I've also grown from start to finish will all 2700, 4000, 5000 and 6500k each at one point or another.

I can say with 100% certainty that it is not spectrum.

Mainly the moisture.

I agree about the moisture. As we both agree its the main culprit.

But i beg to differ about the kelvin. So we can just agree to disagree. I have seen it with my own eyes. An overnight change.
Viparspectra is notorious for having too much blue. Spectrum matters.
The sun rises and falls. The kelvin changes throughout the day. Midday is probably 5-7000k.
That isnt taking the seasons into consideration either.
Not arguing. Just have to disagree.

 

[70's natureboy]

I'll bet if you were using Pro Mix and flourescent tubes you wouldn't be having problems. This new experimental method seems to be a failure.

 

[Roger A. Shrubber]

I'll bet if you were using Pro Mix and flourescent tubes you wouldn't be having problems. This new experimental method seems to be a failure.

hate to say it, but i was thinking pretty much the same thing

 

[whitebb2727]

I agree about the moisture. As we both agree its the main culprit.

But i beg to differ about the kelvin. So we can just agree to disagree. I have seen it with my own eyes. An overnight change.
Viparspectra is notorious for having too much blue. Spectrum matters.
The sun rises and falls. The kelvin changes throughout the day. Midday is probably 5-7000k.
That isnt taking the seasons into consideration either.
Not arguing. Just have to disagree.

Nah. It wasn't the spectrum. Maybe to close but not the spectrum.

I've even used 10,000k bulbs.

I'm telling you there is no way the spectrum caused that unless it produced uv or infared.

https://www.growweedeasy.com/cannabis-light-burn


I can assure you it's how close the light is not the spectrum. 5,000-6500k is very common in agriculture.

Take spring and summer. More blue. Fall and winter have more red.

The sun any time of year will be full spectrum and be way stronger than a little 100 watt light.

You are literally the only person I've heard say spectrum can burn a plants. Besides the obvious uv or ir.

I would like a citation for the claim. I would gladly read it. All info I can find states intensity and to move the light up.

 

[whitebb2727]

I have even started seedlings under 432 watts of t5 with mixed spectrum with uv included and it not burn unless it was too close.

That may be what's wrong. Back the light up. I'm running a cab with four 50 watt cobs and they will bleach and burn full grown plants if too close.

 

[Tim1987]

Nah. It wasn't the spectrum. Maybe to close but not the spectrum.

I've even used 10,000k bulbs.

I'm telling you there is no way the spectrum caused that unless it produced uv or infared.

https://www.growweedeasy.com/cannabis-light-burn


I can assure you it's how close the light is not the spectrum. 5,000-6500k is very common in agriculture.

Take spring and summer. More blue. Fall and winter have more red.

The sun any time of year will be full spectrum and be way stronger than a little 100 watt light.

You are literally the only person I've heard say spectrum can burn a plants. Besides the obvious uv or ir.

I would like a citation for the claim. I would gladly read it. All info I can find states intensity and to move the light up.

Op has wet soil.
30% humidity.
Blue light has a greater effect on plant stomata.

Do you not believe the combination of low humidity. Wet soil, and more open stomata would have an effect?

https://link.springer.com/article/10.1007/BF00390255

I believe it does.

 

[whitebb2727]

Op has wet soil.
30% humidity.
Blue light has a greater effect on plant stomata.

Do you not believe the combination of low humidity. Wet soil, and more open stomata would have an effect?

https://link.springer.com/article/10.1007/BF00390255

Sure it's the moisture.

I'm saying the spectrum has zero to do with it.

That link was for beans and actually states blue would open the stomata more. That would be wanted. The stomata opening or not wouldn't cause burn.

It has zero to due with spectrum. 5,000k is actually about perfect for growing. Has plenty or red, blue and even some green.

The only wavelenght of light that will burn the plant is uv or ir.

 

[whitebb2727]

Op has wet soil.
30% humidity.
Blue light has a greater effect on plant stomata.

Do you not believe the combination of low humidity. Wet soil, and more open stomata would have an effect?

https://link.springer.com/article/10.1007/BF00390255

I believe it does.

Blue light increases the stomata.

If the plant were conserving water the stomata would close.

If anything the blueight is helping rid moisture.