Tomato plant size

[fruitfly]

Tomato plantlets, some in pots, some near the edge of a salad table. The potted ones are growing inches high, the ones in the salad table, with more compost in (though not in depth) are a fraction of the height. In case anyone is wondering why they're in a salad table (not normally used for tall plants) my idea was to train them along the edges, which may or may not work, but the difference in sizes is puzzling.

[Flo]

I wonder if the ones on the salad table can't send roots down deep enough?

[Green Aura]

I don't think they need much depth specifically - think gro-bags - but if they're having to compete with other plants for light, nutrition and water in limited space, that would probably explain it.

[Odsox]

It depends where your salad table is ( I presume outdoors) and where you live (town or country)
Temperatures may have been like summer recently but night time temperatures have been quite low, and tomatoes don't like overnight temperatures below about 10c. They will survive but not thrive.
I wouldn't worry too much, they will almost certainly get going once summer properly arrives.