Our tomato plants are growing rapidly. With tomato plants you have to be careful not to let them grow out of control!
So, what you have to do is to remove any new little sprouting shoots in the already existing branch to stem junctions. This will promote the tomato plants to grow taller and focus their energy on producing tomatoes from one main stem only.
Sometimes keeping track of any side shoots which need pinching out can be tricky, as they grow very fast. Last year we had about three main branches on the tomato plants and they still produced well. So, don’t worry too much if some remain.