3 week old new-shoot burned already?

hi rollitup! hope you're all well and thanks for any help.

as the title says, i'm wondering why the tiny little shoot that is about 3 weeks old and which for the last 2 weeks has been under a lamp, is burning. that is, its little leaves are tinged yellow at the edges. generally the plant looks rather feeble too, to be honest, and hasnt really grown at all since being put under the lamp.

the 300w mars hydro led lamp has always been 65 cm from the plant. today i've just raised it by about another 5 centimetres. to raise it further would need some serious chin stroking and probably a big drill because it's inside a rather impromptu wardrobe set-up.

cheers guys.

amazingly, the plant i planted outside is doing splendidly (to my untrained eyes anyway). i live in switzerland and it's not exactly long hot days here. it's pretty gloomy and wet.

not a lot of info. what kind of medium is the plant in? is the medium amended with anything? have you been feeding it? got a camera? pics always help a lot. if i remember the metric system 65 cm is close to two feet? that seems quite far away

thanks mate for the reply. yes, excuse my lack of info: im a newbie and didnt think to say. with my newbieness in mind, it might not even be that the problem with the plant, which is feebleness and yellow tinged leaves, is lamp burns, especially since you say the light is far away. 65 cm is 2.13 feet.

anyway, to answer your questions: it's in soil. it was a rich, wet soil that the package said is good for garden herbs and lettuce! ive only been feeding it tap water and not very often. maybe once every 5 or 6 days.

i would add something like perlite to lighten up that soil. actually, without pictures, it sort of sounds like it may be time to start feeding, maybe your soil is played out, or you got a handful that didn't have a lot of nutes in it. i'd make up some 1/4 strength nutes to begin with and see if they respond to that, if it makes it worse flush it out and start over, if it makes it better, go to half strength for a couple of feedings then wing it.
also, it might not hurt to just put it under a T5 or a cfl for a few days and see if it perks up. i put seedlings in my veg tent, but i put them off to the side under a T5, where they don't get hit directly by the MH

If your soil is wet, it's probably too wet, and that is causing your problem. Add the perlite as suggested above and ease up on the watering. What size pot do you have it in? Too large a pot will make it difficult for you to regulate the moisture. Make sure you have good drainage.

that's very helpful guys, i really appreciate that!

because the pot it's in is very big, perhaps i went about it all wrong. also i havent got access to any other kind of lights, mine is a very basic set up with a newly bought led.

what do you think of this plan: start again with a new seed. put it in a smaller pot with perlite and dry-ish soil. use nutrients if necessary.

thanks!

start seedlings under a cfl or t5 bulb, don't start them under your led. let them get 4 or 5 sets of leaves before you put them under the real light, then keep the light as close as you can without stressing the plant

Sounds like overwatering.

thanks Olive Drab Green, good to know.

ROger A Shrubber, thanks again. when you say cfl/t5, you mean like the sort of light you put in a reading lamp ie not necessarily a lamp made for plants? when i do that, shall i keep it all in the wardrobe or shall i put the new seeds in the window as well as under this cfl/ t5 lamp?

and just to clarify: we can also conclude it's not lamp burns that's making the leaves yellow?

also: ive got a plant growing in the window and soon enough it will be four or five sets of leaves. shall i transfer that to under the lamp when it is? and obviously to veg conditions ie 20/4 cycle or thereabouts. cheers!

yes, plants don't need that intense a light to sprout under, a T5 flourescent tube in the 5K+ color scale or a 25 watt cfl in the same range till the plants are growing good. when they have good healthy leaves and aren't stretching, then you can put them under the regular light. i usually wait till i top them the first time, i pinch off the 7th set, give it a few days to get over it, then it goes in the regular area.
the ones in the solo cups under the t5s will stay in those cups about 10-14 days, then another 10-14 in 2 qt. size, and move them next to the ones in the solos, not into the bright part of the MH light, then into the one gallons and a topping. they stay there for another 10-14 before the flip, and a final transplant into 3 gallon hempies. so depending on the plant veg could be anywhere from 30-45 days.
i just transplanted the one on the left from a 2 qt into the one gallon pot and topped it. i'll leave it on the edge of the mh till it perks up

your set-up looks awesome tbh.

i just need to confirm and clarify a few things so i know that ive understood:

- your seedlings never see sunlight, they just sit under the flourescent T5 or 25 watt cfl?

- do you turn this flourescent/cfl light on/off in the 20/4 veg cycle? or is it on constantly?

- when these seedlings have grown a bit and have sprouted the 7th set of leaves, you then cut off this seventh set of leaves? this is called 'topping' them?

- more specifically, your veg state takes approx 30 - 45 days and this you divide into 4 stages:
1. seedling grown in a cup
2. then transplanted to a bigger pot which you put on the edge of your main grow lamp area ie not directly in its beam.
3. transplant to a bigger one gallon pot and cut the seventh (or therabouts) leaves. DOES THE PLANT NOW GO INTO THE FULL BEAM OF THE GROW LAMP?
4. transplant to a 3 gallon pot and start the flowering cycle by changing the lamp on/off time?

and let me ask these two follow ups:
- your medium is entirely perlite?
- do you think i can transplant young plants grown under sunlight for a while into the lamp area? if yes, not until there are 6-ish sets of leaves though?

thanks for your help. nice one!

yeah, no sunlight, they live in the tents their whole life. theres nothing wrong with a few hours of real sun a day but thats impossible where i live.
i was using a 20/4 veg cycle, but i honestly think i'm getting better results with an 18/6 cycle. it gives the roots more time to grow, and better roots = better yields.
when the 7th set of leaves is still coming up, still together in the middle of the plant, i just pinch it off with my fingernails. they slow down for a few days, then they start to get bushy, secondary branches start to grow and fill in the plant.
when they go in the one gallons, i top them, and give them a few days still on the edge of the strong light to get over it, when they seem to be growing again, then they get put directly under the MH.
you can change the light/light timer, but i have another tent i just move them to to flower.
look up hempie buckets, thats what i use, except i do use 100% perlite, where the original recipe calls for 25% vermiculite. as long as you water at least every other day you don't need it.
if the plants have already been under the sun for a while, they should be ok under your light, just keep an eye on them and if they seem stressed move them a little farther away

Hi @zurich..

These below things you should maintain and balance it.

Week 3 flowering
Light Quantity - 100%
Light distance - 1.6 ft (50cm)
Light Duration - 12 hours
Temperature Day / Night - 78.1ºF / 64.4ºF (26ºC/18ºC)
Humidity level - 60%
pH level - 6.0
EC - 1.4

And Not enough (or too much) light - burned or crinkled leaves, too much space between nodes, tall seedlings that fall over

Not Enough Light = Stretched, “Leggy,” Tall Seedlings

Too Much Light = Burned, Crinkled Leaves

Stretched, “Leggy,” Tall Seedlings - Give More Light!

Thanks

youve really done me good here with your diligent help. one more thing: when you say 'top them' you mean sort of prune them? ie cut off their top leaves? and also you are saying that when when you use perlite, it's important to water the plants more ie every two days?

to ya!

hey Barbara Martin, nice one.

very interesting that: im growing a plant in the window and its definitely a 'stretched leggy tall seedling' looking for light. its growing slowly-ish and has big internodal distances. i didnt expect much from it anyway so i am not disappointed. im aiming to get buds from my lamp seedling, albeit i've messed that up a bit and probably will now start again.

funnily enough, the healthiest plant of all, one that looks like something from the photos (kind of) is one that is outside. and the funny thing is, i live in switzerland where its just as gloomy as it is bright!

Barbara, when you say 'week 3 flowering' are you saying that '3 weeks from first growth is the flowering stage' or are you saying 'the third week of the flowering stage'? you mean the second one? im not yet quite at the flowering stage yet. but ive started to dream about it already. (true).

@Roger A Shrubber: im currently getting organized for a new start and will soon buy the cfl bulb on amazon. i really dont want to start hassling you at the microdetail level but anyway (lol!): when you say 5k does the light therefore need to be between 5 and 6 k or do you mean it can be anything over 5k. for example ive found a nice grow lamp cfl bulb that is 6400 k.

one last question, sorry ... (this is my third btw added to the thread): does the cfl bulb have to be 25 watt or thereabouts. for example there are bulbs that are 60 watts on amazon. maybethats too high a wattage.

6400 is fine, anything over 5k is pretty much for veg, anything under 4k is pretty much for flowering, 4500 ish can be used for both, but not as good as having over 5k or under 4k.
yeah, when i say topping, i mean just pinching off the very top set of leaves on the plant, i use my fingernails, but you could use scissors.
i wouldn't go much over 30 watts for the bulb you're going to use for seedlings/cuttings, you want that light close to the plants so they don't stretch too much to reach the light, if its a very strong light, it could burn your plants

brilliant!
i'll order all that stuff and then its: Operation Grow All Over Again.

thanks Roger, thanks rollitup!