That's... bizarre. I've had one or two seedlings do that, but I've never seen anything like entire trays doing that. Any other symptoms? Were your seed leaves chlorotic? Was there any purpling? How was your soil moisture? When you transplanted your tomatoes, did you see any signs of root rot?

I prefer to keep tomatoes at warmer than 67, but that shouldn't be causing this...

I'm not familiar with a manure based container medium - what exactly is it?

manure based medium is great as a part of a starter soil, probably not the whole thing. That's no mistake though...just a preferred method/opinion. Anyways, first off, too much light/heat conbination after they sprouted. I would have taken the light up to about 1ft and transplanted to a non-peat based potting mix (no sand) as soon as the second leaf set had shown. The peat-based method with that much heat & light has burnt those poor plants to a crisp. Immediately take them, in their current containers (you need to transplant to a solid (cups, usually) form/container that you can poke a few holes in the bottom of. Put them outdoors, if at all possible (weather permitting) not in the direct sun for the first few days. Fetilize with a water-based solution & make sure it never touches the plant (above soil, which I reccomend a mixture of your manure-based & maybe some sphagnum moss or a little compost, but not too pure.). Then, water thoroughly so the stuff is soaking out the holes in bottom. When they dry a day or so later, water again (bit less...maybe 1/2 inch)...repeat process & place in moderate sunlight after a few days...then eventually in full sunlight after a week or so. I guarantee you within 2 weeks your plants will have sprung back to life quite well (and maybe have 3-4 sets of leaves). You may loose a few, but you'll keep most of them. Otherwise, IMO, they will be gone within 7 days.

- Steve

Couple of things :

I removed heat after starter leaves sprouted. Did not use it or a fan nor a heater the whole time.

No sign of purpling. Period. Only yellowing of starter leaves and then true leaves later. But leaves did not yellow until after living at least three weeks on the plant each.

Manure based medium : Google for MooNure.

Lights started at 10" above tips. After 15-20 days of no growth, I moved them closer to the leaves.

I used 1/4 of suggested strength light liquid fertilizer from the bottom up, soil already wet. I did this no more than twice this entire process and not until true leaves formed.

Soil moisture: no damping off, and only once did I see fungus gnats which quickly passed. I am aware that peat pots cannot be trusted and you must check soil for moisture. I do not saturate my soil and do not typically keep the top of the soil damp. I water from thw bottom up.

The lid was removed from greenhouse tray promptly after initial germination.

Oh and no signs of root rot. Roots were actually very healthy looking and well formed, starting to reach out of the bottom of the tray.

Yea...MooNure...Home Depot...$2 a bag. Good for part of your mix...add MG dry peat instead of what I said earlier.

Mine did exactly the same thing! Started under lights, too. Also, strong root formation. In desperation, about 10 days ago, I planted outside in a raised bed just to try and save them. Planted 4 to a square foot knowing I'd have to move, obviously, if they even recovered.

Well, they recovered! The ones I kept, that is. Some I pitched as totally hopeless.

I don't know what happened to this whole batch either, but you might try planting some out and giving some cover (mine are under row covers).

Ironically, the toms I winter-sowed went gangbusters and are much larger than the ones I started inside GUL. I'll pass on that next year and just WS them all.

Prof

The steer manure our local Home Depot carries is something different, different brand - blend of manure and aged wood chips. I've never seen this one but their website states -

Moo-Nure® can be used around plants, in the planting beds and as a soil conditioner or clay breaker.

Potting Soil
Mix with topsoil, sand, Hydrocks® or perlite.
Seed Flats, Hot Beds, Greenhouses
Mix 1 part compost, 4 part soil, 1 part sand.

But not having transplanted into compost, I couldn't say if it directly contributed to your odd seedling growth.

This is a good example of proper tomato seedling care.

Steve's Garden

Peace - Steve

Steve - from your link, I found this page which has to be just about the most informative webpage I think anyone has ever created regarding growing tomatoes. I searched high and low for something like this the past couple of years and came up emptyhanded. Very good stuff!

If all else fails, I have another four of each variety tomato that've sprouted down in the basement as of ~10 days ago, so no huge loss...but I really wanted to definitively know what caused this so I could prevent in the future. Sounds like the MooNure alone (for repotting) was a poor idea from the getgo. May've made one or two other mistakes along the way as well.

Thanks y'all. If anyone else has any commentary or thoughts, please do share. Three years later and I'm still a newb at this.

ahhh, yes...catman's page. Very nice & well layed out and quite informative. =) He's a smart dude. I'd definitely reccomend it. Mine's more of a personal garden diary/blog of sorts.

touching back on this because i had a radical turnaround.

i took the seedlings, forked them out, planted them in drink cups with holes in the bottom using Miracle Grow for a medium, all were planted halfway up the stem.

in just five days, i have already seen 4 new true leaves sprout, and everything really perk up from the transition. mind you, this is after 5+ weeks of no new growth, so ... wow!

clearly, i should've transplanted sooner, and shouldn't have used pure manure for a transplant medium.

lesson learned!

Glad to hear your plants are doing good! =)

I appreciate your help, Steve - spot on advice!

In looking at the photo - my reaction is that the light source is inadequate. How old are your bulbs? Shouldn't use them for more than 2 years as a grow light. Set the timer for a 16 hours/day on cycle. The lumen output drops off dramatically.

I start mine in the seed packs, then into 12 oz red drink cups, when about 3 inches tall, planting deeply. then after about 4 weeks they go out to the coldframe. a few weeks later - into the 1/2gallon milk containers, so that by mid May have nice big root systems to plant in the garden

i keep the lights about 2 inches above the top leaves.
also, the peat or manure pots you have - i've never been able to keep the moisture regulated - their either too dry or wet. I did some peat pot, some plastic pot w/seed start mix, and some w/spaghnm moss in small self water plastic containers - only the peat pots had problems.