I am in Dallas (TX) zone 8.
I have used Wall O' Waters all last year.
I sucessfully transplanted my Tomatoes plants on February 11th and tehy grew fantastic ! When the plant grow some of the leaves will go out of the Wall O'Water and they may turn a little yellow if the temperature is too cold ... but the plant will still be ok. I really had a MILLIONS of tomatoes starting my plants in side Wall O' Water so early.
Good luck

Add a little bucket with water inside your hoop house. All the plants will benefit from the moisture of the water. Good luck

Hello from Dallas (zone 8).
I normally transplant out my first tomatoes crop on February 11th.
It is still cold and you will need to use protection. I use the WALL O WATER around each plant.
If you don't have protection you can transplant them in March.
Starting in February I normally have lots of tomatoes by the beginning of May.
In Dallas we have two growing seasons. You can transplant out a second crop at the end of June.
If you are starting from seeds inside, you shall start at the beginning of January and at the beginning of May in order to transplant the tomatoes in February and June.
In this way I truly have "tons of tomatoes". Alessandra