Question
I am in wisconsin, started a bunch of tomatoes from seed, large and small variety and put them in 5 quart ice cream containers with holes in the bottom for water and for roots to grow out of.  I would like to place these in the ground.  Will this work, I heard it can.  They are about 2' high now inside. I wonder how many and how large the holes should be. I was hoping to use the containers year after year and have less weeding (with black plastic).

Answer
I am assuming the containers are cardboard. I don't see how they will last year after year. They will break down with the moisture.
You will also want to have plenty of room for the roots to grow. Tomatoes have very large roots. If the containers are plastic, they will be like keeping them in a container, which could restrict their full growth. It would work best if you dig a very deep hole about double the depth of the container, then fill it halfway with good potting soil. cut the bottom out of the container, then put it on the soil, fill it with soil and plant your tomato in it. The roots will go down to the lower soil and the water will be directed to the roots by the container. Fertilize often and keep it moist. Make sure they get full all day sun but protect tender leaves from burning on hot days. Black plastic will also keep the soil warmer, which will help the tomato to grow better, but don't let it cover the roots of the tomatoes, or they will dry out.