If you want to grow huge tomatoes, follow the lead of Gordon Graham, who holds the Guiness Book of World Records for his 7 lb. 12 oz. whopper. Choose varieties known for producing large fruits like Big Zac or Giant Belgium. Most huge varieties are indeterminate types, meaning they grow all season on long, rambling vines. Native to South America, tomatoes love moist, fluffy soil and warm, sunny days.
Make rich, fluffly soil by spreading 2 to 3 inches of compost on your garden location. Shovel the soil to a depth of 6 inches, mixing the compost into the ground. Dig a hole deep enough for your plant and gently place your plant in the hole. Backfill dirt in the hole, pushing the soil down firmly to remove any air pockets. Dilute starter solution according to package directions and apply 1 cup to the soil around the plant to prevent plant shock and give the tomato a good start.
Place a wall of water over your young plant and fill the water pockets 2/3 full with water. Adjust the wall of water so it sits like a teepee over the plant. Remove the wall of water when nighttime temperatures are reliably above 65 degrees F.
Stake or cage your tomato plant to support heavy vines and fruits. Drive the stake or cage 12 inches into the soil. Cut old pantyhose legs into rings and tie them loosely around the tomato vines and the stake. As the plant grows, provide additional support by tying up the heavy vines.
Fertilize your tomato plant with a balanced fertilizer or fish emulsion two to three weeks after planting and every four to six weeks thereafter. Follow package directions and keep granular fertilizer 4 inches away from the base of the plant to avoid root burn.
Water your tomato 1 inch every week. Tomatoes need a consistently moist soil to thrive. Allowing them to wilt and then overwatering them will slow growth and cause disease. Water slowly with soaker hoses or a trickling hose. Watering in the evening promotes disease, so water only in the morning. Adjust your watering schedule for very rainy or dry weather.
Prune your tomato, cutting off all but one strong stem. Pinch off any suckers that grow between the main stem and leaves. As the tomato plant matures, remove all but two or three fruits, choosing the older fruits at the bottom of the plant and closest to the main stem.