Stem problems on seedlings

[BillyBuddWiseR]

I've had great success germinating seeds. My problem is that many of my seedlings end up with stems the size of thin thread just laying on top of the dirt.
Pam I overwatering? Ph too high?

[tlranger]

Sounds like damping off, Good compost is my answer, but have read here, shovel or weezard wrote about using small amount of h2o2 in water as a preventative. Going to try myself.:jointsmile:

[TANKJR]

It's not a big deal really...mine do this all the time and I just prop them up with bamboo skewers or something similar for a few weeks until they get their stems caught up with the rest of the plant. There are several ways to strengthen stems. Best way IMHO is to keep a very small slow blowing fan on them indirectly...just so they barely move. I don't really know about this other technique, but I've read if you gently shake the stem base for about 10-20 seconds each day, the plant will mistake it for "wind" and work to strengthen the stems...however, I'm not brave enough to do that to my 2-3 day old sprouts! There may be other ways as well, but I'm ripped right now and can't remember! DOH! Hope this helps! PH shouldn't be an issue, because you have that exactly right all along, right?????

[Shovelhandle]

I don't see the seedlings laying down. I wouldn't be too happy either. I have not had to use a splint to hold them up, but I have added soil around the stems before.

[Weezard]

Dampening off is more prevalent with stretched stems.
Here's a case where LEDs shine.

If you add about 15Watts worth of blue light, it shortens the internodes and keeps the stem thick.
That, and a small oscillating fan will serve you well.

Now, who can tell me why my last germinations went weird?
The root came out and hung a U turn as usual.
Then some of them made an O turn, then some uh-oh turns.
Spiraled into a knot just below the surface.

Planted pointy end up as usual.
In coco, PH'ed water. ~82 F. ~ 58% RH.
Mixture of daylight and LED to shorten the dark period.
'snot the LED.
Only added the led when the early poppers began to stretch.
The knotty ones were, of course, slower to break the surface by 3 days.
So, were already squirrelly before getting lit.

Whipped out my 'scope.
Can't see any soil critters.

How about it guys?
Any ideas?

Aloha,

Weeze

[Weezard]

Hang on!
Just saw your other post.
Your problem is most likely heat if you are using the HPS for seedlings.

That color temperature causes stretch.
And the heat produced is radiant.
The plants see it as IR and reflected "far red".
That demands stretch.

Shut off the HPS for now, seedlings do not need, and can not use, that many lumens, and they are spectrum sensitive as well.
A couple 23 Watt, cold white CFL are plenty and will fix your elongation.
Save the HPS for when you see the first preflowers.

Aloha,
W.