Tomato seedlings not growing

I planted two different kinds of bush (determinant) tomatoes: Defiant and Mega Bite. Put them into the 1 x 1 inch peat pots and inserted those into the plastic trays that have slits on the bottom to allow water to be drawn up into the plant. Put some water in bottom of tray, as well as watered the seeds and covered them with a clear dome. Seedlings popped up very quickly - 100% success rate. Lights are on about 12 hours per day and are close to the tops of the seedlings to prevent them getting leggy. But now, with their first leaves still on them, they seem to have “stalled” for the last two weeks. Any ideas why this is happening? Do I need to transplant them already? Do they need kelp this early? Any thoughts are appreciated and thanks in advance.

I would definitely give them some fertilizer if you haven’t already.

In my experience, this is what tomatoes (and peppers) do…they seem to come up quickly and then ‘sit’ for several weeks (maybe getting their roots going?). Yes, give them a little food, and I think they’re going to be fine.

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Bottom heat sure helped in getting our tomatoes to sprout in less than a week, and growing well. Linda is out transplanting them into bigger containers now. With no bottom heat it will take longer. And our experience suggests some seeds do better overall than others - no thoughts as to why though.

I remember my Grandmother used to sprout tomato seeds on damp paper towel in the kitchen before planting them. Worked for her!

Hi Sylvia
By first leaves I presume you mean the cotyledons (smooth entire edges) and not the first true (serrated and lobed) leaves. If this is the case a slight delay before the emergence of the first true leaves is normal.
I grow grow mine is a similar manner in small 1x1 plastic multi packs, with heat to aid germination. After 3 true leaves are formed I transplant mine into 4 " pots and move them into the greenhouse. When transplanting you can deep plant them up to the cotyledons to reduce legginess. Good luck and best regards,
Frank H

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What ratio of NPK for seedlings?

@slystone did your seedlings ever start to grow? I’m having a similar issue. So strange. Started them March 23 on a heating mat. Perfect germination and now they are stuck with just one set of true leaves after a month of growing. They look healthy otherwise. Maybe just developing some really healthy roots? Would love to hear how yours fared.

Nope - they never progressed, so they went into the compost pile (if they grow in there, I can always plant them again :stuck_out_tongue_closed_eyes:). I thought it was too late to start them by seed again (Brian Minter said differently a few weeks ago), so I bought plants, which are doing very well.

I have no idea what to say about this phenomenon. Never happened to me before. Maybe one of our tomato experts can tell us what happened.

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This is probably a silly question, but what kind of lights do you have them under? I think regular LEDs don’t give off the wavelength that plants need.

Not a silly question at all Jono. I can’t speak for Lorna (she is a better gardener than I am, I believe), but they were under lights that came with my grow tray, so I can only assume they are the appropriate lights for plants. Currently, the tomato plants I bought plus the Fuchsia are doing very well under these lights - both blooming, in fact. I have started plants from seeds in this grow system before, so I can’t see that being the problem.

Hi all, so happy to have some discussion on this! They were started on a heat mat and then under grow lights (specifically bought grow lights) for about a week). For the past 5-6 weeks they’ve been in a south facing window, and when it’s warm enough, they go outside in the sun. I’m starting to think it’s the water! I’ve given them a weak shot of fish fertilizer three times…maybe something else would work better. And Sylvia, I am a big novice gardener, learning all the time :slight_smile: