Growing upside-down tomatoes makes sense for many gardeners. If you lack garden space and enjoy growing vegetables in containers, upside-down gardening is a newer twist on the old standard container growing. Prevent upside-down tomatoes from breaking by pruning them carefully. When you remove some of the stems from the upside-down plants, you create a stronger and more energized plant that will produce more and bigger tomatoes.
Allow the upside-down tomato plant to grow freely in the planter until you begin to see blossoms on the vines.
Remove 1/3 of the entire plant. Clip off the side branches where they intersect with the main tomato plant stem. As you remove one-third of the entire plant, stagger the stems you choose to remove so the plant remains even on all sides.
Cut back the longest stems by 1/3. Remove 1/3 of these stems to leave 2/3 of the stems continuing to grow in the plant.