Problem With Seedlings?

[threepwood]

these were planted some 7ish days ago in fresh potting soil, with seeds presoaked in paper tissue to sprout. Then left indoors for 2 days until they started emerging from the soil then placed outside in a small greenhouse. But they seem to be dying? leaves turning yellow and sickly, on some just one leaf, on others the whole plant almost.

Could this be excess sun? it has been really hot here the last few days. 20+ C and no clouds. Maybe too much for such young plants? or is it something else?

Any help appreciated

 

[Ar.BsG]

Ye way to much sun lot of people ben haveing this problem . Yes more light is better but you have the sun . Just leave them in the shade and don't get water on the leafs on a sunny day .......

 

[jammie]

Yep that does look like light burn. Ar was all over that !

 

[threepwood]

Alright, thanks for the replies guys, the situation have been remedied, hope the plants recover!

Ciao

 

[Ignignokt]

Actually, that soil looks pretty wet. And the stunned examples have salt burn at the leaf ends.

Looks to me like a probable PH or too much nutrient problem. You can see what looks like the beginning of salt crusting on some of the last photos.

They will probably continue to die in the shade, just a bit slower. The first picture is toast, just awaiting fungus.

Start seedlings out of the full sun, don't use anything but water until the second set of true leaves are at least an inch or so. Most potting soil is pretty hot and not good for popping seeds. Adding any nutrient (unless it is coco or some other neutral substrate) pushes hot soil into being actually poison to seedlings. They will start and die just at the same stage as your examples, above.

 

[threepwood]

Just a little update.

They are doing better now, also culled some dead ones, planted new ones etc.

Can someone tell if they are growing alright? Last year we had big problems with them stretching too tall, not getting bushy etc, just a tall stem with only much leaf growth at the top really. Is that happening now or am i being hysterical?

 

[Ar.BsG]

when you repot them just repot them cover the stems up with dirt as needed. When they Are a couple weeks old they need stronger light you'll have to get a light or put them outside .

 

[Madbud]

They look happy!

 

[threepwood]

Alight, got it covered then i think.

Thanks for the advice everyone!

 

[Ignignokt]

stretching too tall, not getting bushy etc, just a tall stem with only much leaf growth at the top really

Not enough blue spectrum. Natural light is great, however windows (glass) blocks the blue portion. Notice there is no one trying to get a tan where the plants sit. Many newer windows may have a coating to block the IR (heat) spectrum that may be a thin film. So - growing inside behind glass using the natural light (sunlight) will get ya some very stretchy plants. Greenhouse?

Excessive stretch is from lack of blue spectrum, a signal to the plant it is in shade or blocked from direct sun or light source exposure. Long term changes in light quality/intensity/length exposures generate a hormonal response. You know, like flowering. The more mature the plant ( think of clones ) the more pronounced are the responses to light period and quality even in smaller plants.

Light source quality is critical to growing to optimal potential. There are important parts of the spectrum that plants respond to that are not in the visible spectrum that is typically called PAR. You can find some interesting albeit more technical discussions in other threads.

This one is pretty good, from @Homesteader https://www.thcfarmer.com/community/threads/photosynthesis.88405/page-2#post-2047163