Sounds like lack of adequate light could be your problem. Get the lights as close as you can to the tops of the plants without burning them, and leave them on 18 hours a day. Your soil mix sounds like it might be quite water retentive, but doesn't sound like you need to add fertilizer at this point. You do need to allow the soil to dry out a little before watering and never get soggy.

Water hasn't been a huge issue. I've seen no signs of stress. I was thinking the lights, but I'm also concerned about how much energy I'm burning each day with 6 lights like that...even if they are fluorescent. I've never used artificial lighting before, so I'm not sure what the cost is gonna be vs buying seedlings from the farmers market. Oh well! I'll try upping the lighting to 14-18 hours a day.

I would suspect your growing medium before your lights.

Is there a reason that you have top soil mixed in to your containers? It's usually a pretty bad idea for container growing, especially for young seedlings. It's not light enough nor porous enough for their roots to grow very well. Plus unless you sterilized it, there may be pathogens in the soil.

My soil mix is about 1/3 peat moss, 1/3 composted manure, and 1/3 top soil.

There is the majority of your problem. Month old seed lings should be several inches tall and have at least 2 sets of true leaves.

Both soil and manure compact in containers. That leads to very poor drainage, root rot, and stunted plants. Soil-less potting mix only is used in containers and especially so with seed starting.

Then there is the manure. Even well aged manures can easily burn the roots on young seedlings. They don't tolerate it at all well.

Seedlings growing in a proper container mix don't require any fertilizer until after they develop their second set of true leaves and even then only a light well-diluted dose.

Suggest you might want to review some of the great FAQ how-to over on the Growing from Seed forum here.

I'd strongly suggest your seedlings be carefully transplanted into new containers filled with a good quality soil-less potting mix - many brands available - and I'd rinse off as much as possible of the current mix in the process.

Dave

Here is a link that might be useful: Growing from Seed forum

I appreciate the input. I doubt I will go as far as to change out 50+ plants into new containers, but I can certainly heed these ideas for future advice.

The mix that I'm growing them in is actually very loose and drains very well. And the composted manure is (upon reading the bag more carefully) a mix of various things that includes manure. Either way, the plants appear healthy enough, and don't appear stressed.

I should also note that I grew tomatoes/peppers last year using the same soil mixture, but I placed the containers outside during the day and brought them in at night, and I ended up with some fantastic plants. They took awhile to take off, but I figured it was because the temperature was cool, and they weren't getting full sun at the time. I just wanted to start much earlier this year, so I opted for the fluorescent lights, and I'm just now noticing the discrepancy between my plants and other folks.

Um, I'm confused. It sounds like you're saying that the same thing happened last year, where the conditions were different except you used the same growing medium, but the medium can't be the source of slow growth you are seeing? If it isn't temperature, and your water and light are adequate, then I think the growing medium is what is left. Try a mild dose of water soluble fertilizer on a plant or two and see if you get a result. It sounds like even if the nutrients are there, the plants are not able to access them well. Otherwise, if your sacrificial plants wither and die with extra fertilizer, then you have too much and have burned the roots. But without pictures, I lean towards the first. Cheers!

About 80% of all plant problems begin with soils. I would say that is your culprit. Tomato seedlings do not need much in the way of nutrients in the first 4 weeks as they live off of the little bit of energy provided to them in the seed. Nearly every time I have fertilized tomato seedlings I have had problems; thats even using a dilute solution only added once. If I were you, I would try to make a seed starting mix made out of 50/50 pete moss and vermiculite with a little lime to blanace ph and provide minerals. Then no fertilizer, manure, mineral soil, compost etc. And also make sure you use clean new planting treys to prevent disease.

I do agree that your soil is not the best. But since you have already said you are not going to repot 50 plants, all you can do is make the best of it. And that would involve being very careful about not watering too much, not using any fertilizer and increasing the light. Fluorescent lights do not use that much electricity. I use 400 watts of lighting for 18 hours a day for growing seedlings and I don't think it costs me much more than a few dollars a month.

I do appreciate all the input, if this thread isn't too far down to still get read.

I understand that my soil isn't ideal, but it wasn't entirely from not doing my reading first. I use it because I wanted to avoid multiple transplanting steps and have a good source of nutrients, essentially, and it seemed to work last year just fine (topping off 2/3 filled containers with more soil mixture as the seedlings grow). The main difference between this year and last has been the light source, and I am using 6500K "daylight" bulbs.

I know pics would be ideal, but most of the tomato seedlings look....withered a little bit, so to speak. The soil is slightly moist, but by no means wet, and I water about 2/3 of a shot glass per cup (think classic, small, styrofoam cup with holes poked in it in the bottom and sides) every 2-3 days. If it help at all, vs some of the late germinating seedlings, the older ones appear slightly yellow-green in color, although not to the extent of pictures of over-watered seedlings I've found online. Thanks if anyone has any further input.

Great input from everyone here. These two links may help also.
http://www.tomatodirt.com/tomato-seedlings.html
http://www.tomatodirt.com/seed-starting-mix.html

Here is a link that might be useful: Seed starting mix for tomatoes: what ingredients are important

looks like your effort to save work backfired ,, I would get some good sterilized potting medium, plant some seeds hold them covered at 80 degrees . they will pop up in a matter of days.
. than give them 16hrs of light (I let the leaves nearly touch the bulbs) drop temps to the 70-75 degree range.. start fertilizing with a weak solution.once the get 3-4 inches..
these seedlings will far outperform the stunted ones.

you don't want to rely on the stunted seedlings for your entire season ... it's not worth it ..plus there is a good chance that bad pathogens may have been introduced.

now is the time to get off on the right foot.

at the least.... start a second batch per my recommendations and compare(and have backups )

I have a similar but different issue. I started my seeds from saved seed from last year inside, then moved them outside. I planted them in a raised bed that has a mixture of aged composted manure and humis, perlite, and Scott's premium top soil which has organics in it. As well as pine bark mulch. This was to emulate the TAPLA mix I've read of here.
My seedlings are growing very slowly, and some are yellowing. They receive well over 8 hours or sun. However we have had quite a bit of rain here. I am try a foliage feeding of neptunes harvest fish and seaweed fertilizer.
Please advise!

The lights have to be right on top of the plants, but as said before I'd consider seed starting mix next year. You have a thick medium and maybe acidic. I'm fairly new to this, but this year I got my hands on pro mix, night and day compared to what I was using and you'll have the same experience if you compare. Good luck!

Classic overwatering symptoms:

"My seedlings are growing very slowly, and some are yellowing."

"However we have had quite a bit of rain here."

firegrip,

It sounds like you may have water logged soil, which can kill the roots of tomatoes. Dig down about 4 - 6" in the bed, is the soil wet, just right or dry? If it is wet and you are not watering, I think you will find that as the weather moderates and things dry out, your tomatoes will take off.

I doubt that a foliar feeding would be useful at this time, if your plants are water logged, they aren't likely to be happy to get sprayed with more liquid. I don't know how much of the nutrients they'll absorb.

Betsy

Your problem is definitely your mix. Tomatoes will grow fine and be very healthy when grown in a heavy mix. They just grow very slowly. I actually start mine out in garden soil and just start a month early.

Once you put them in the ground, they will take off. Next year, you need to either ditch the garden soil and add vermiculite or ditch the other stuff and just grow with dirt and accept the slow growth.

As if you needed more confirmation, its the mix. And for future referance, repotting up seedlings helps them grow numerous feeder roots. They may survive, but as has been noted, they are not likely to thrive. Repotting is your best course of action.