Some people prune tomato plants and some just let them grow wild. So why might you want to prune your tomato plants?
For larger tomatoes
If you prune the plants more growth will go into the tomato and not vine production.
When growing tomatoes vertical or in hanging baskets
Plants can become heavy so when growing them vertical on a trellis, tomato cage or in a hanging basket you may want to prune them to lighten the plant and weight.
Grandpa Joes Pruning tips
Grandpa Joe grew his tomatoes vertically and used this pruning method. he also applied a lot of compost and aged fertilizer, followed by a heavy layer of mulch.
Prune the young tomato plant to form a “Y” fork low to the ground. Train these two stalks up a trellis made of wood or string. Don’t prune off any more suckers. Keep the vine growing vigorously to shade the tomatoes and protect them from sunburn.
Yes tomatoes can suffer too much from direct sun after they have been pruned.
Pruning can help you produce a larger crop of tomatoes. But it takes a few year pruning to find a method that works for you area and garden climate.