They look a bit leggy. Get light.

Not sure where you are, and when you can plant outside, but my rule of thumb is that the pot you grow them in, as seedlings, better be at least of the same order of size as the plant it's holding. For tomatoes, they can tolerate being somewhat root bound, because when you plant them outside, just plant them deep, to form new roots along the stem. One the plants are a few inches tall, I start them on dilute fertilizer.

Thanks! I"m in NJ and from what I read people usually wait a few more weeks to begin this but I have no patience. I've read the term "leggy" but didn't know what it meant. I'll get more light right now. I'm not sure if you recommended replanting them now or simply waiting until spring. Also, since they are indeed 3 inches tall, very diluted fert? Thanks Dan.

I'd pot them up now to 4" pots of the large solo cup (with drain holes). They probably should have been potted up a week or 2 ago. When you pot them up, plant them up to about 1/2" below the lowest leaves so bury them stems and that will promote root growth along the stem. You can fertilize weekly and weakly (diluted to no more than 1/4 strength of the recommended amount.

After potting up if they continue to grow leggy like they are now you might want to pot them up again to 1/2 gallon pots.

It would be much easier to answer your questions if you can add your general location to your user profile like most of us do. If you are in the northern half of the country you shouldn't even have started your tomatoes yet and if that's the case I would go ahead and start some new ones so you don't have to baby those for another couple months.

Noooooo!!!! I have no self control so there is no way I'm tossing these. Live and learn. I'll start new seeds in a month but see what happens with these. It'll give me a chance to practice my new obsession. I'm off today so what I'll do is pot them today in 4" pots and put them under my grow light in the basement. I'll also start to weakly fertilize them once a week. I know this isn't ideal but like I said, this is practice. Is there anything I should look for as these start to grow? Thanks!!!

Is there anything I should look for as these start to grow?

In a month or so they will probably start to put out blossoms. I would pinch those off until you transplant them out to the garden. I hope you have a lot of space height wise under your grow lights because they are going to be at least 18" tall by May. Good luck!

Sometimes a south facing window will provide more light than a grow light. It can also help to have a light fan on it to help the plant from getting too tall and thin. Even a ceiling fan would help. When plants do not get enough light they put all their energy to getting taller to get to the light. With florescent lights the bulbs should be about 2 inches above the top leaves.

Yes, you're headed for a succession of repottings. You can go to 4-inch pots now, but in a few weeks they'll need something larger. As they get larger and larger it's going to be harder and harder to give them enough light. Even with grow light 2-inches above the leaves, those are just the top-most leaves. For a small number of small plants, planting outside before last frost is possible, in that there are easy ways to protect them. For larger plants, frost protection becomes quite difficult.

You could "top" them in a few weeks to keep them shorter, whereby grow-lights would work better. Just cut them off to half-height. They'd just start to form new branches at the cut-off point. Wouldn't hurt them the long run. Yep. Not fun.

That makes a lot of sense. If you have bigger pots, and appropriate soil, use 'em. Of course, bigger pots means that they are more spread out, and it's going to take more light to do them right.

If you put it in the 4 inch pot now, later you could plant the tomato deeper in the bigger pot, if the tomato was getting leggy.

You could also leave an inch or two space from the top of the pot and as the tomato got taller, just add more potting mix to help straighten up the plant.

Plus if you put it in a too big pot now you risk drowning the root system. Little roots in a big pot of wet potting mix tend to rot.

Dave

What I would do right now is add some dump soil, probably to cover at least 1/3 of the stem. Your soil looks pretty wet, so do not water the soil you added. This additional soil will help stabilize leggy ( too long stem without leaves) plants and also promote new roots. And I will leave the plants in that pot for now. You will have to transplant them much later, or may be even directly to the garden.

I usually pot up twice before the tomato plant goes into the ground or its final large pot. My understanding is that the roots do not like too much area as they begin to grow, others here know the science of that and Dave probably has it nailed with his comment above. I start with very small individual containers (1" maybe), then up to something a little bigger (3"?), then one more increase, those red plastic drink cups. HTH.