Watering Tomatoes in Pots

Water the soil slowly and thoroughly until it is evenly moist immediately after planting. Add more soil to the pot if it settles from the water, and water it again to moisten the added soil. Continue adding soil and watering until the soil is within 3/4 inch of the pot's edge and evenly moist. Keep the soil consistently evenly moist by watering it once or twice daily. As a rule, watering the young tomatoes until water runs through the bottom drainage holes gives them the water they need.

Check tomato plants twice daily for watering needs as they mature, starting in the morning. Stick your finger into the soil down to 1 inch deep, and if the soil sticks to your finger, it does not need water, but if it does not stick, water it until water runs out the bottom drainage holes. The amount of water needed varies between a quart to a gallon depending on the pot size, weather conditions and plant size. Avoid getting water on the leaves because wet leaves are more susceptible to fungus and mildew.

Water dry soil immediately before fertilizing the tomatoes, wetting the soil thoroughly until water runs out of the bottom drainage holes. On average, tomatoes are fed a water soluble fertilizer with a composition of 20-20-20 or 15-30-15. Apply weekly beginning in midseason. Rinse fertilizer residue from the tomato's leaves.