Training Tomatoes to Climb

This obviously does not apply if you're using a Topsy Turvy Tomato Planter, but if you're using traditional garden or pot techniques, simply pinch off the lower branches and plant the tomato deep. Then, as the tomato grows, pinch off the little axils that grow between the branches. Each axil will grow into a new vine if allowed. If you have space constraints and need to grow your tomatoes vertically, it's important to let the main vine grow as tall as possible. Just keep the axils pinched out.

Here's a great book for tips on growing vertically due to space constraints: