It is a bit leggy but not too bad. How many weeks has it been since sown?

I would start hardening the plant off ASAP. It is plenty large enough. Being outdoors will do it some good as far as thickening up that stem.

The plant looks pretty good to me. The leaves are a little bit yellowish, so maybe the potting soil run out of nitrogen. And it is a little leggy, but not bad at all. I would harden and transplant it outside soon since you are Zone 6.

We're in zone 6 also and planted our seedlings 2 weeks ago. Always a roll of the dice... Hardening off takes about 2 weeks, gradually increasing the duration of time outdoors. After seedlings are about 3 weeks old, we give them strong sunlight outside during the day to increase growth, bringing them in at night. We also use fluorescent lights (a pair of regular shoplight fixtures side-by-side, regular 4' tubes, 6500K), with the tubes set right on top of the leaves. Even doing that the leaves only get 2500 foot-candles of light, about 1/4 of full sunlight. Faster and denser growth and very little legginess. If your plants are set deep to the upper leaves, they will sprout new roots along the stem and form a strong and healthy plant. Good luck!

Tomato looks fine. But it won't want to stay in that cup for another two weeks. It's time to harden off/plant out, or move to a larger pot. Plant out after threat of frost is past. USDA hardiness zone is not a predictor of the date of last frost. (It really isn't a predictor of much, for summer gardening ...) Need to look that up based on exactly where you are. There are websites where you can do that easily by zip code.

Thank you for all comments. Two people said this is "leggy". Is there anything I can do about this? Or do I just have to accept it?

The reason the plant is leggy is because it is reaching for the light, so put your lights no more than a couple of inches above the plant next time.

At planting time, you can set the plant nice and deep (as someone else already suggested) and it will root all along the stem.

Linda

We used to grow seedlings by a south facing window, with a reflector behind them, but they still got leggy. Switching to fluorescent shop lights fixed the problem. With them side-by-side, we have 4 tubes in a 1 foot width. For this year, just accept what you have and plant them deep or in a trench. For next year, put those tubes right down on the leaves and the plants will be much more compact. I just measured our lights and against the lights it is 3100 foot-candles while 2" away it is 1300 foot-candles (sunlight is about 10,000 foot-candles). We bought a pair of ratcheting pulleys from an online auction for $3.50 that makes it much easier to adjust the height of the lights (search for Grow Light Rope Ratchet Hanger).

It's not really that leggy. But the way you avoid legginess under fluorescent lights is to put the light just an inch or two away from the foliage. Many beginners put the lights up high, so it is conveniently "sorta shining on" the plants. That's not good enough. Not bright enough. Need the bulb RIGHT ON TOP OF the plant. Of course, that doesn't work with incandescent bulbs, because you'll burn the plants.

"Am I correct that this plant still needs to be indoors another few weeks?"

Why? The plant itself is clearly ready. Weird weather or something? Surely in your zone it is time to harden off and plant unless your weather is really abnormal. Even zone 5 gardeners are planting theirs as the weather permits.

Dave

I agree, though the plant looks a bit leggy but it is ok.

And yes, it is plant out size. But first it needs to be hardened off. That is gradually introducing it to the outdoor conditions ( sun, wind, cold ..), starting few hours a day and finally whole day and night.

Sey

Thank you all

should I remove the Cotyledons? If I did, I could plant this tomato plant deeper.