Your plants look very healthy! Tomatoes don't like cold and will just mark time till it warms up. I'd put them out on warmer days and bring in at night.

First step is to transplant into larger pots. Now. They are now too big for the original pots that I see in the pictures. Larger pots means larger surface area, and your lights will be less effective. So yes, take them outside to get some sun when conditions permit.

Only a freeze will kill tomatoes. 5c simply means slow growth. Some would say that cold temperatures actually stunt them permanently. But I've never experienced that.

@daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa) I just did what you said. i was able to transplant 5 of the plants into bigger pots (their permanent place, 4x30cm diameter, 1x20cm diameter)

Rest still stay as they are. I have no more available space as you can see in picture. in considiration of heavy wind and cold days in Czech Republic, i probably will not put them outisde till May.

And next year i will definetely not start seeds that early...

The ones you didn't transplant, if they are still alive by May, will be seriously root-bound in those tiny containers. Badly root-bound plants are likely to be stunted and, if they survive, will take longer to recover when outside. Not sure it will be worth planting them out.

One survival strategy would be to vigorously prune the tops and roots, and replant in the same containers. Cut away the roots that are starting to circle the inside of the container.

If you have no room, I wouldn't bother too much more with them. Those semi-transparent round containers could just have a 'collar' added to them to make them taller, then fill with more potting mix and the stem will root. They'd love it. :)

I would cut off the tops and root them in water (or in potting mix if you prefer). That will make them a lot shorter.

Jak se máš byuri

If you leave your tomato seedlings in the same containers they will be fine, assuming you keep them watered, not over watered... I grow my seedlings in a 36 cell tray and never transplant them to bigger containers. Once you put them in the ground they'll be fine. Don't transplant them to the garden till after your last frost date has passed. From my experience if you don't kill the seedlings you'll get production. If your tomatoes are short they may loose a few days, If they're too leggy just bury them deeper in the ground when you plant them.

As far as your question about direct seeding in the ground, some will grow even if over wintered in the ground. The problem is that the percentage that germinate is probably so low that you may not see results with the number of seed you have left.

As said, when you have a nice sunny warm day. Put them out in the sun. Start with only an hour outside, and increase the time over the following days outside. That's called hardening off.

Good luck and enjoy your tomatoes.

Well, seriously root-bound plants will not be healthy. That's all there is to it. A certain amount of foliage on top needs a certain amount of soil space below that is providing nutrients. That's true in a seedling pot, or in the ground. Having said that, it is true that root-bound plants are easier to transplant, because the root-ball holds together better if roots are tying it all up. As a result, you end up with less root breakage.

Just look and see. Seriously root-bound plants will have roots winding in circles around the periphery. Roots poking out of the bottom drain holes are a bad sign as well. Those roots are looking for nutrients, but have nowhere to go. Root-bound plants frequently will be stunted, and the lower leaves may look brown.

May I ask what you plan on doing with a dozen cherry tomato plants? The sungolds I used to grow would give me a gallon every couple of days! Had to stop growing them when I retired and didn't have a place to give them away! And I only grew ONE plant!

I grow a large beefsteak tomato called Marianna's Peace which is said to have originated from Czecholslavakia which has a delicious full tomato flavor. I'd recommend it and many other beefsteak tomato. Pink Brandywine, Dester, Mortgage Lifter. I don't know what's available there, but it's not too late to plant tomatoes. I haven't started any here yer and assume you may be in a similar climate

In summer 2018 I had heaps of cherry tomatoes from 2 or 3 plants, and I dehydrated what we couldn't eat fresh or give away. The dried halves were delicious, like dried fruit. They were great in winter salads

I have twelve cherry plants, and I just give the fruit away. Neighbors love them. But this isn't relevant to the question from the OP.

all you folks are great. such a value in this forum!

regarding tomato consumption, i agree about dried tomato solution. they are very tasty when you prepare with nice olive oil-garlic-oregano.

approximately howmany tomato i can have from 1 cherry tomato plant? 100-200 ?

ps: @John D Zn6a PIT Pa ,

ahoj : )

The number of cherries that you get will depend a lot on sunlight and fertilization, and to some extent, variety. 100-200 from one plant isn't an unreasonable optimal number, but that will be the case over several months.