Consistently too tall Seedlings

We're a few growers in a very hot and humid part of the world (South East Asia) that have a consistent problem with seedlings grown from seed, whether in a soil mix, a soil less mix or in a starter cube.

As you can see from the pictures of these three latest seedlings, they're unnaturally tall. They grew almost instantly to hit the roof of the dome and here a day after I've moved them out of the dome (third day), they're almost 4 inches tall!
The seeds were three healthy and big mottled bag seeds, a mix of blueberry cheese and a local plant I think.
In the dome they were watered twice daily, with mineral water with a drop of Superthrive and a milliliter Clonex Cloning Solution and kept at 85%+ humidity. They were germinated in tissue paper in water, between two plates and once they popped, were planted in the cubes (I didn't want to germinate in there, since I didn't know which seeds would be good).
The temperature in the room is between 25 and 30 degree celcius, with an AC on when it gets too hot. With the AC on the humidity falls to 50-60%, but otherwise it's at 75%+.

The thing is, my two mates have the same issues, one is growing outdoors and the other indoor, but both get lanky, tall seedlings.
Since most strains I read about are grown in Europe or the US, they're usually grown in much colder climates and here it's very rarely less than 30 degree celcius, so I figured they were getting too much heat and I had the AC on, which helped the issue with a few batches, though not this last.

The plants will survive I'm sure. Worst case scenario they fall over and I tie them up and after a few days or a week they pick up again.

HOWEVER, I'd like to know why they get that tall ? ? ?

most likeky your light is too weak or too far awY from them. if u are using weak lighting i would ditch the dome and vet the bulbs as close as u can without burning the plant

purplehays1 said:

most likeky your light is too weak or too far awY from them. if u are using weak lighting i would ditch the dome and vet the bulbs as close as u can without burning the plant

Click to expand...

more than likely right

I agree with the guys above. From what I have read, stretch almost always seems to be tied to light being too far away or too weak.

AlcoholicO said:

We're a few growers in a very hot and humid part of the world (South East Asia) that have a consistent problem with seedlings grown from seed, whether in a soil mix, a soil less mix or in a starter cube.

As you can see from the pictures of these three latest seedlings, they're unnaturally tall. They grew almost instantly to hit the roof of the dome and here a day after I've moved them out of the dome (third day), they're almost 4 inches tall!
The seeds were three healthy and big mottled bag seeds, a mix of blueberry cheese and a local plant I think.
In the dome they were watered twice daily, with mineral water with a drop of Superthrive and a milliliter Clonex Cloning Solution and kept at 85%+ humidity. They were germinated in tissue paper in water, between two plates and once they popped, were planted in the cubes (I didn't want to germinate in there, since I didn't know which seeds would be good).
The temperature in the room is between 25 and 30 degree celcius, with an AC on when it gets too hot. With the AC on the humidity falls to 50-60%, but otherwise it's at 75%+.

The thing is, my two mates have the same issues, one is growing outdoors and the other indoor, but both get lanky, tall seedlings.
Since most strains I read about are grown in Europe or the US, they're usually grown in much colder climates and here it's very rarely less than 30 degree celcius, so I figured they were getting too much heat and I had the AC on, which helped the issue with a few batches, though not this last.

The plants will survive I'm sure. Worst case scenario they fall over and I tie them up and after a few days or a week they pick up again.

HOWEVER, I'd like to know why they get that tall ? ? ?

Click to expand...

Remove the dome soon as they pop and put a light fan on em to help harden em off no air movement will do that theres really no need for a dome. clones u dome
id pot em now and put em so about 1 inch sticks out of soil and see how ya go I live in australia similar temps ive grown seedlings under a 10w fishtank light lol

When you transplant them burry them up to a few centimeters of the first leaves and thatl fix the stretch. Itl grow roots out of the buried stem and they be gem.

Yup, get the light closer.

They are stretching searching for light, make sure you have a decent cfl grow light (150w) and make sure this is 4-6 inches above seedlings and they will stop stretching...

when the little white root is about 1cm long
place it tail end into the cube so only the seed shell is poking out
and put it under the light some of them will stretch more than others

3 days germination 1st day of light


2nd day of light


3rd day of light


peace

Thanks to everyone for commenting. I already thought it might be the light or heat and thus turned on the AC and put them under a light, but as I've been much to afraid to give them TOO much light, I've been doing the opposite it seems. So under the light immedeately or at the very least as soon as they're above ground - I'll do another batch in cubes soon and see if I indeed learned something useful and new

Thanks to skunkd0c - that looks perfect, with the little cubes and tooth picks - miniature grow. So cute...
What kind of cubes are you using there?
I've successfully gotten my hands on the grodan gro-block, 1,5inch, as well as the starter cubes shown above, made from peat moss and bark. HOWEVER, I had to order all this online at a very high price (e.g. the cubes used above cost 7$+30$ for shipping for 24!). THEREFORE I'm curious as to what kind of insulating rockwool and the like, can be used to grow, as that's all that's available here...

skunkd0c said:

when the little white root is about 1cm long
place it tail end into the cube so only the seed shell is poking out
and put it under the light some of them will stretch more than others

Click to expand...

they are 1 inch rockwool cubes
(Grodan Small Cuttings Seed Cubes 48 per tray) (£5.00

the rockwool used for loft/attic insulation is no good for growing
for 2 main reasons the loft insulation may of been treated with chemicals
even if it hasn't loft insulation is not dense enough
rockwool needs to be very dense to be used for growing or it will break down and become mushy
and waterlogged , it needs to have this high density to keep its solid block like structure
and be able to keep a good level of oxygen in its structure when fully wet and still keep its shape
and density

i guess its possible you could find some untreated loft insulation and pack it in tightly to try to increase the density
but still i think this would not be good as the roots that grow through this would have less oxygen around them
because of water logging/saturation in places

rockwool is also used for sound insulation this type is more like horticultural rockwool
it might even be denser you would have to research it
but it works out more expensive so its easier/cheaper to just use the rockwool that is designed for growing
its pretty cheap from the hydro shops
my plants do not grow in the rockwool for longer than a few weeks i only use the little cubes to keep the plants upright and to start them off
once the roots grow out of the bottom of the blocks they grow in the nft channel

Remove the dome soon as they pop and put a light fan on em to help harden em off no air movement will do that theres really no need for a dome. clones u dome
id pot em now and put em so about 1 inch sticks out of soil and see how ya go I live in australia similar temps ive grown seedlings under a 10w fishtank light lol

Click to expand...

Yes, next batch I will remove the dome as soon as they pop out and put them under a light fan with a LOT more light - maybe put them in the outskirts of the light from my Apollo 4 (used to keep 3 critical plus from flowering till they're a bit taller, then move them outside to flower).

skunkd0c said:

they are 1 inch rockwool cubes
(Grodan Small Cuttings Seed Cubes 48 per tray) (£5.00

the rockwool used for loft/attic insulation is no good for growing
for 2 main reasons the loft insulation may of been treated with chemicals
even if it hasn't loft insulation is not dense enough
rockwool needs to be very dense to be used for growing or it will break down and become mushy
and waterlogged , it needs to have this high density to keep its solid block like structure
and be able to keep a good level of oxygen in its structure when fully wet and still keep its shape
and density

i guess its possible you could find some untreated loft insulation and pack it in tightly to try to increase the density
but still i think this would not be good as the roots that grow through this would have less oxygen around them
because of water logging/saturation in places

rockwool is also used for sound insulation this type is more like horticultural rockwool
it might even be denser you would have to research it
but it works out more expensive so its easier/cheaper to just use the rockwool that is designed for growing
its pretty cheap from the hydro shops
my plants do not grow in the rockwool for longer than a few weeks i only use the little cubes to keep the plants upright and to start them off
once the roots grow out of the bottom of the blocks they grow in the nft channel

Click to expand...

Thanx for the details skunkd0c, are those pictures of roots! Coming out of cubes? That's a mad set of roots!
Where I am in the world (South East Asia), people are and have been growing weed for thousands of years, but as they primarily use it as pig or human food and only after that, for smoking (so most is for eating, without getting noticeably stoned, while a bit is for smoking) and there are simply not the same things available in a western country or at the very least a country that's not a third world country, like where I am.
I found several hydro shops, but they don't have cubes and the only hydro food available is what they make homemade, while the only soil fertilizer I've found, is from Thailand, Vietnam or Cambodia and possibly China.
Through extensive searching, driving and internet usage, I've found Rockwool for insulation, 40, 60 and 80Kg per squaremeter, so 80 being the densest. However, as you mention, it's likely treated and probably not dense enough and I HAVE to buy a bale, to even be allowed to check it out (for them to take it from the warehouse to the shop).

Ebay has allowed me to get grodan cubes, but that was 1.5 inch cubes and with transport, not exactly cheap (12$ for 45, but then 15$ shipping).
I also got the root riot organic plant starter cubes used in this post to make them tall and lanky babies and that was equally expensive (24 cubes in tray for 9$ with 10$ shipping).


Next batch I then have to decide if I'll do either of these ways or another.
Prior to method, Germinate in plate with tissue paper, since I tried germinating two OG Kush seeds in a root riot cube each, as opposed to let them pop and then insert the tap root into the hole and these two still haven't popped after 5 days!

1. Plant in Soil (1 part perlite, 1/2 part vermiculite and then unbaked, unsterilized dirt, with seeds and all sorts of other stuff in it - the only soil I've found so far that's not backyard soil). This works, but they usually take a week longer to get to vegetative, probably due to the quality of the dirt. When I tried in only perlite/vermiculite they fared even worse.
In these plastic cups, I don't feed them anything (just water with a bit of superthrive) until their first true leaves show and after that only very very little...
Since I get 100% survival rate, even if they're a tad stunted, using soil, I will continue to plant 1/3 to 50% in soil, till I can do cubes with a better survival rate.

2. Plant in Root Riot Organic Plant Starter Cubes, as these three lanky babies were. Out of 10 germinated (after germination in plate with tissue and water), only 8 popped out of their shell in 3 days and of these I planted the 6 best looking, but of these 6, only 3 came out of the cube. This I think has to do with the seed shell being in the way of the plant or maybe the tap root got damaged when I inserted the whole thing, WITH the taproot out, in the hole of the root riot cube.
However, I'm reluctant to move these starter cubes into a hydro setup, since I don't know how or if they'll affect the water and as such, I'm planning to transfer the 3 lanky babies plus if they pop, the two OG Kush, to larger soil based pots.

3. Plant in Gro-block Grodan starter cubes. Got these expensively and my mate is PH neutralizing a couple to be used with the remaining OG Kush.
I would try the method with sticking the tap root into the hole and add a tooth pick - seems to work very friggin well.
Getting these or the Root Riot Organic cubes is expensive, BUT if I can get up to a 90%+ survival rate with plants that are NOT stunted from stress, I'll happily spend a little extra.

As to experimenting with insulating Rockwool, I simply don't think it would work (after what skunkd0c told me here in this thread) and getting a whole bale (a few square meter at least) and then having to wash it, seems to be a bit over the top. It would, however, mean a vast infinite source of cheap cubes.

Pictures of the soil based chemical food I'm using until I can find a DIY organic option (going to a special market today, so who knows what I'll find)...

these look fine and healthy mate you just didn't get them under the light quick enough
or close enough to the light
4-6 inch away from a 125w cfl or 2ft away from a 250 mh would be enough light
get them under the light when the tap root is 1 cm


they can grow this out if you help support them
they will fill in and the stretch will not be so bad as they grow

when i started there were no fancy liquid foods
standard powered hydro food works well
it can be bought directly from hydro garden nurseries but normally needs to be bought in large amounts
bottle foods are convenient but not necessary
as long as its nitrate based (designed for hydro) and includes all trace elements/macros it will be fine

i notice from this shot below your seedlings are in a wet environment
are you spraying seedlings ?



it is not a good idea imo to get seedlings wet, they do not need high humidity
they require a tiny amount of water
the amount of moisture in the blocks will be enough
keeping the seedling wet will slow its development and could cause further problems
of mold/fungus

have you looked at the hempy bucket thing ?this is a simple passive hydro thing
that would not require much equipment
or look at NFT this hydro method can use any medium and only requires a small aquarium type pump

Ehm, admittedly I was actually spraying them and not for any good reason, it's just that I was baked and I like spraying stuff...
Since one would use high humidity and a dome for clones in cubes, I somehow thought that was a good idea.

Next time though, I wanna try with the tap root inserted in the cube or rather starter cube for me.
I started two OG Kush in cubes like these, but they still haven't come out (5th or 6th day I think today) and since the seeds were rather expensive, I'm thinking I should try and get it out and germinate it in a plate instead, though by now that would probably kill it. Just wish I had germinated before hand.

BTW I'm using sunlight in the window, when available and otherwise I got an Apollo 4 from Cidly (full spectrum with 60 x 3watt LED's). I haven't got any CFL's or MH's. I wanted to get some though, but I had a hard time figuring out which CFL to get or where to get MH's and the Apollo is doing a stellar job lighting wise...

I still can't believe how many and how nice the roots are on your plants!

I got a bubble bucket setup with 4 plants and a cloner with 15 cutlings at a mates place. I build them, he takes care of it, so he's more in the know growing wise. I'm going to his tomorrow, to build one more cloner, upgrade another cloner and build a large aeroponics bucket system. We're also doing a modified version of Stinkbud's aeroponics system build exclusively from PVC pipe, some time over the weekend. I'll get some pictures of those as well and post.

This is very educational

Sorry mate not sure weather i was clear about starting the seeds off

i never put the seeds inside the cubes until the tap root has grown to around 1cm long
taproot might only be 1 or 2 mm in length when they first have germinated on day 2 or 3 inside the dome,

they can stay until day 4 or until the taproot has grown
bigger (1cm)

i place the seed on top of the cube on its side i push it firmly so its making full contact with the rockwool
but is never under the surface
i make sure the cubes are fully wet
i put them in a dome with a little bit of water at the bottom of the dome/ propagator
i put this in a dark place, the majority of the seeds will germinate in 2-3 days, anything that takes longer than 5-7 days
is not normally as viable . often i throw these away as they are just too far behind the others

i leave the seeds as they are until the tap root is about 1cm or so then i carefully place the seedling root side down into the cube
i use something to lightly push the rockwool around the taproot so it is making contact with the rockwool
as the holes that are already in the cubes are too large and the seedling could dry out

i push it as far down as i can without damaging the tap root
sometimes if the taproot is very curly or awkward shape i will cut the rockwool cube down the middle putting the long taproot inside and fold the rockwool back together it will stay together with a rubber band or something

only the seed shell is poking out of the top of the rockwool that is the aim ideally
although sometimes its a little awkward to push the taproot fully into the cube
its ok if they stand out a little bit from the cube they will still stretch but its minimal

they can go back in the propagator at this stage for another 1 or two days to let other seeds catch up, or they can go straight under the light, each seedling has a different stretch rate if they stretch a little ill put them under the light, i try to keep them even but its not easy
some seeds will always be ahead of others due to faster early development
although often slower seedlings can catch up during veg and even end up
much larger during flower

im not for telling folk what to do with their own plants/seedlings
but i would ask you not to spray them anymore lol
they do not need it, and it will only do them harm not good

peace

The OG Kush germinating in the last two cubes finally popped out and somewhat slowly.
I had to liberate the plant from the shell, but she seems to be fine now an hour after the operation (I'll add another picture later).
Her sister is a little bit more slow, but is almost above ground, probably behind by a day . . .
They're not domed and haven't been since I found out I shouldn't. I pour a bit of mineral water (PH neutral) with a pinch of clonex and superthrive in it over them a few times a day - no spraying.