The University of Illinois lists the tomato as the most popular plant grown in home gardens. Tomatoes are easy to grow, produce a large quantity of fruit and have small space requirements. Most home gardeners want to harvest large-sized fruit from their garden tomato plants, which is accomplished with proper care and pruning during the growing season. These maintenance steps force the plant to focus energy toward growth during the early season followed by fruit production.
Remove all tomato flowers that blossom while the plant is growing. Fruit size decreases if the plant is growing in size while trying to produce fruit. Cutting off the flowers will force energy towards strong plant growth. Mature plants force energy towards fruit production and increased fruit size.
Cut off sucker branches that form under the first set of flower clusters. Suckers are small leaves forming in the crotch of main branches. Remove the suckers as soon as they form to prevent excessive branch growth, which decreases fruit size.
Fertilize tomato plants with 1 tbsp. ammonium nitrate fertilizer for each plant once the green tomatoes are approximately 1 inch in diameter. Apply the fertilizer again three weeks and 6 weeks after the first application. Water the soil thoroughly after each application to increase the absorption rate.
Provide supplemental water to the tomato plant during the growing season. Keep the soil evenly moist to prevent plant stress, which decreases fruit production and size. Water the soil instead of the spraying the plant to lower the risk of disease.
Cut off the top and all leaf tips approximately 30 days prior to the first frost in the fall season. Removing the growing portions of the plant will force the energy into growing and ripening the fruit that remains on the plant.