I grew up watching and helping my great grandfather Ben, tend to his huge garden in Milton, PA along the banks of the Susquehana River. We would carry water down the alley to his huge garden in 1 gallon milk jugs. The photo to the left is Ben's garden circa 1972. He always grew 2 favorite tomato varieties, Henderson's Winsall and Burpee Big Boy. We would water them, harvest tomatoes and we would always pinch the 'suckers'.
Fast forward 50 years to our gardens and heirloom tomato program at
Foster Hill Farm. We grow over 150 varieties of tomatoes. Most are heirloom varieties that are large, indeterminate plants. We are growing in the ground, in large nursery pots outside and in the same large pots in the greenhouse. So do we pinch the suckers?
No. Much to what would be Ben's dismay we do not pinch the suckers. The sucker is a small branch that starts from the 'V' where a fruit bearing branch connects to the main stem. It will not set any fruit. The suckers provide leaf coverage for fruit once it does set to keep the fruit from damage from the sun. The additional foliage helps the plant grow.
What we have found is that it is important to prune enough foliage throughout the plant to allow good air circulation. If there is too much foliage and even too much fruit it is necessary to prune the foliage and even remove some of the fruit to allow the remaining fruit to grow to full size. Special care is taken to leave enough of a foliage canopy to protect the fruit and support the plant. The photo above is a plant from our trials that needs to have some fruit removed and a little foliage removed to promote air circulation and growth of the individual tomatoes. Plants with too much foliage create a perfect environment for fungal and bacterial issues.
In addition to keeping the plant pruned throughout the middle and top of the vine we also trim any leaves and branches from the bottom of the plant so that they do not touch the soil. Pathogens travel through the air but also are easily transferred from the soil to the plant.
As the plant ages through the growing season it is normal for leaves to yellow at the bottom of the plant. These leaves should be removed and the plant kept as clean and free from rotting foliage as possible.