When tomato plants are first transplanted to the garden it is often suggested that the plant be buried ½ way up the plant. The reason for this is to promote a large root ball. Another suggestion that is heard frequently is trim the lower leaves on the plant once it is established, but why?
Prevent Fungus/Mold
Fungus and Mold grow on plants when there is low air circulation, high moisture and nutrients on the leaves. Trimming the lower branches of a tomato plants helps prevent fungus and mold by stopping water and soil from splashing back up on the lower leaves and allowing more air to circulate.
Pest Control
Many pest that attack tomatoes will attack from the bottom first. Trimming the lower leaves discourages some pests. This technique does not stop any pest, but it does seem to cut down on the number of pests found on a plant.
Direct Energy to Fruit
Many of the lower leaves on a tomato plant in the home garden tend to not receive much light and start to die off. This causes the plant to direct energy to keeping that part of the plant alive and robs energy from fruit production.
So while a tomato plant can be healthy and productive with no trimming at all, removing the lower branches can be quite helpful!
