This is my third attempt at trying to grow tomatoes. Thus far I have been unsuccessful. This is the first time I am trying to grow cherry tomatoes and want to know when I should transfer into the ground or containers. I have attached a picture and would appreciate any advice or tips. Thank you! Zone 9

They look good! What has been the problem in the past? Damping off? Failure to thrive? I do notice there's lots of dry spots in the potting soil. Roots won't grow in dry spots - soak the soil thoroughly but don't let them sit in water.

I would let them get quite a bit bigger before transplanting them.

Personally... I would set them out just as soon as I could...
Those are the type of containers that you don't have to remove the plant from...
When is your last frost date?
Looks like it's passed (or soon will) for your area according to the site calculator.

Caution. Those peat pots DO NOT rot away in my experience. Keep the peat moist. You'll want to pot in bigger pots or outside within a couple weeks. Tomatoes grow fast. Even cherry tomatoes often grow big big plants.
Again my advice is remove the peat pot.
I used peat one year, planted out in garden, plants were stunted and roots could not grow through the peat. Even though peat was buried.

You could begin exposing them to more outside like conditions but gradually, and keep the peat moist! Push them all together, some water in the tray, they'll dry faster once opened and getting brighter light and more airflow.

My experience with those peat pots.... You have to make sure that entire pot is buried...

I haven't noticed any performance issues in my plantings.

stone said: My experience with those peat pots.... You have to make sure that entire pot is buried...

I haven't noticed any performance issues in my plantings.

All I can say is, I did, and I did.
YMMV.

Sounds like an opportunity for bmassaro21 to some side by side testing...
Plant out some with the peat pots, and some removed from pots.

I haven't used peat pots in years, mainly because of the issues that I had with the roots not being able to grow through them. I would suggest, when planting them out, if you don't remove them from the peat pots, make sure to water them well and at least poke your fingers through the sides and bottoms of the pots to provide openings for the roots, and then, as Stone said, be sure to completely bury the peat pot (don't leave the upper edge sticking up above the soil line).

When I used peat pots (in the distant past - in my experience, the roots never got out of the pots), I rip off the bottoms and score the sides with a knife.

As with all tomato plants make sure you add some water-soluble calcium salts to prevent end rot of your tomatoes. I use fast dissolving lime. Proper watering is required to make sure the calcium gets to the roots.

"Below, we've listed some excellent sources of calcium for tomato plants:
Wood ash.
Shells (eggs, oysters, and clams)
Dolomite.
Lime (calcium carbonate)
Bone meal.
Gypsum.
Calcium nitrate.
Mar 1, 2023

The Importance Of Calcium For Tomato Plants (+ Growing Tips)"

Kind of on the theme of others, I always ripped off the top of the pot so no peat was above the soil surface when planted. I also roughed up the pot so the root had someplace to go before the pot broke down. There were times when cleaning the garden in the fall, the pots were still intact and breaking the pot really mattered. You can plant the tomatoes deep, they will sprout roots from the stem.

I would give them another week and then plant up to a 4" or 6" container with good potting soil. Tomatoes are warm season plants and do not like cold weather/soil. Put under lights after transplanting and start hardening off when overnight temps are 46 degrees F or 8C. Plant out when daytime temps are in at least 70f/20 degrees C. You will also need to cage them or support them as they will sprawl and not do as well. Good Luck!

@bmassaro21 to the forum! Sorry you're having problems growing tomatoes from seed! What issues do you encounter?
I agree they're too young to be transplanted right now. Also please do not plant them still in the peat pots. I HATE those things; they do not decompose quickly enough. Not to mention when they stay wet a lot they can get moldy and I've seen them with some kind of maggots on them. Foam or plastic drink cups work great to start tomatoes in and they are much cheaper than those crummy peat things.
Good luck with your plants, maybe it's time to give them a diluted dose of fertilize?

Not ready to set out yet. Cut off bottom leaves and add more soil up to second leaves. Let them grow larger and cut lower leaves and more compost or potting soil, this can be repeated as grows. Put on larger cup, I like 16oz plastic cup with 3small v's cut at bottom of cup. Put whole cup in clear plastic cup. Water and place in clear cup. Water should cover small v's. From draining wait till you get good roots and when plant out, plant almost up to leaves. I put straw around them. Cups can be washed and reused.