What temperature for seedlings?

I would have thought that seedlings could withstand temps of up to 25 degrees celcius but at 22 degrees celcius i get heat stress to the leaves.

Now all strains i grow are heavily indica dominant and in flowering seem to be good up to 25 degrees celcius but for the seedling and young vegetative period i really have to hit between 16 to 20 degrees for optimal growth.

Most grow guides and info tells me to aim for 21 to 22 degrees centigrade whereas i have always been told 18 degrees as a rule of thumb for seedlings. I also suppose clones might be different with rooting temperatures than seedlings.

Anybody care to say what they think ideal temps should be for indica strains at these stages. Peace

not sure but i had temp problems when i built my box but me mother always said 20-22 for seedlings and 22- 29 for the rest...

i like to keep mine about 65/66f..

welshsmoker said:

i like to keep mine about 65/66f..

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About 18 to 20 degrees centigrade then. Peace

I germ and keep them at 85+(root zone) 78-80 air temps for the first week or so.

watchhowIdoit said:

I germ and keep them at 85+(root zone) 78-80 air temps for the first week or so.

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Wow, very high temps, my strain will not allow me to get this high. Im the other end of the scale, mine germ and grow at 16 to 18 degrees best for first 3 weeks. Peace

Your rabbits are eating the cannabis leaves? That's such a great picture

Kingrow1 said:

Wow, very high temps, my strain will not allow me to get this high. Im the other end of the scale, mine germ and grow at 16 to 18 degrees best for first 3 weeks. Peace

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Not high at all, optimal IMO and that of seasoned gardeners...growth below the soil is what should be focused on early in a plants lifes. The upper growth will follow and catch up once the root system is ready to support it....

watchhowIdoit said:

Not high at all, optimal IMO and that of seasoned gardeners...growth below the soil is what should be focused on early in a plants lifes. The upper growth will follow and catch up once the root system is ready to support it....

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Ah i think the trick of higher temps lies in having good air circulation or air exchange, this i find has allowed me to reach over 22 degrees celcius with no problems. Was it just that i had a small pc fan before and my seedlings didnt have enough air circulation to grow in high temps, now i have a desk top fan and they can take the higher temps better?? Peace

It's your poll. I am pretty sure the results will be accurate. IMO 77-79 is perfect for them.

Abouts 30 degrees celcius then roughly speaking then bigjesse1922, i have seen clones get that high before but not seedlings. Dose the higher temps give better and faster growth i wonders?? Peace

Mine are growing in 70 lights off and 80-85 in the daytime.

Bwpz said:

Mine are growing in 70 lights off and 80-85 in the daytime.

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God damn mine are jealous, i have few seedling problems but feel i am growing at the wrong lattitude to you guys!lol! I suppose im just gona have to bump the temps and see what happens, as long as i keep the fan on the lights i think they'll be ok. I cant imagine them growing much faster than they do, any extra growth they can get will be much appreciated and make for shorter veg times. Peace

First few weeks is more about keeping the root zone warm to encourage root development.

I do both clones and seeds as close to 80f as I can keep them. After the 3'ed set of leafs I try to keep the plants under 80f and the roots under 70f. But the room can hit 90 and be ok. I didn't take any ground temps this year in the green house. the out side temp were hitting 100+ Inside the green house with both ends open and two fans was hitting 106-110. Plant did fine. We got a cool spell for a few weeks and temps were in the 70's then bam 100 for a week. that seemed to hurt them a little. Slowed the flowering down. They kicked back and are doing good now.

WoW....Amazing High Temps With some of you guys. I if mine were at 80 for a full day they would be dead. and im using led and a ac and good fans.
i just upped mine from 70 to 72 because of the sloooow grouth young seedlings.
Hoping it is the cold that has them growing like shi+ .
Any Tips on why i would have issues with young seedlings?
would love some ideas of causes just on average plant. Thanks

ooROYBOYoo said:

WoW....Amazing High Temps With some of you guys. I if mine were at 80 for a full day they would be dead. and im using led and a ac and good fans.
i just upped mine from 70 to 72 because of the sloooow grouth young seedlings.
Hoping it is the cold that has them growing like shi+ .
Any Tips on why i would have issues with young seedlings?
would love some ideas of causes just on average plant. Thanks

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Dude i made this thread many many years ago - i was such a nice inquisitive guy then.


You need to make a thread, give details and pictures and see what peeps think.

HEY!!!! You be nice!!!! He is worried about his seedlings....