Backyard Aquaponics
A place to discuss aquaponics

I seeded a tray of sponge media (i can't remember the name of it) with lettuce seeds. After 4 weeks the growth was so slow that I was concerned they would never do anything. I put them in the dwc hoping they would grow better. That was a mistake. Almost all of them have grown very little and most of them have such spindly, weak stems that they simply fall over.

ph 6.8
ammonia 0
nitrite 0
nitrate 40-60

water temp is around 55-65 F

I have air stones in the dwc under the raft.

Not all of the plants are falling over, just most of the lettuce. My concern is, these are bibb lettuces that should be forming a nice, compact head of lettuce. Any ideas? This is the first time I have used the sponge media to start seeds.

It looks like the seedlings have been reaching for the light. If you have improved their conditions the problem will mostly self correct, at least it has for me in the past.

I'd be more concerned about why they are growing slowly rather than their form.

+1

Could be the light, they do look pretty spindly

Hey Chris-

My best guess is:
Light- were these raised in doors before you move them into the raft? In shade?
Temp- low water temps will slow growth. Try to get it in the 70's or be prepared for slower growth

Bibb can still head up after stretching as a seedling but you need to get it into stronger direct light as soon as possible. At this point the stretched stem may lay horizontal, harden up and your heads will grow upright, they will just be a few inches off center from the middle of your net cup hole.

thanks everyone. i started the seeds indoors under lights. the lights were 2" above the plants. The problem is it took the seedlings almost a month to even get half the size they are now. I decided to just put them in the dwc but I guess the polycarb roofing is not allowing enough light in. plus, the sun is still a little low in the sky where I'm at and this greenhouse doesn't get direct, overhead light yet from the sun. I'll just leave them be for now and see if things improve as the sun moves across the sky this Spring.

Not hyjacking but will the leggy lettuce ever recover if its bigger /older and has laid over? Mine went leggy when I was away from home and it 4" tall and laid over... Better to restart or just leave it?
Thank you.

as long as it is alive and gets more light then it will probably recover over time. See Ryan's response above.

Thanks Chris and Ryan for taking your time to answer.

viewtopic.php?f=3&t=24673 Check out the pics from my grow I have very low watt lights and my romaine got really spindly and fell over. If you look they just correct themselves and just grow up towards the light again. I just harvested two of them and they were an L shape haha. Plants are amazing, give them the right conditions and they will run with it.

Moved the lettuce from the DWC to the media bed, it's much better and like predicted above straightening out and growing normal. Thanks for the suport.