Beware – water runs straight through well-draining soil medium. When water drips out of the container bottom, you may think you’re watering thoroughly, but much of the moisture is lost. Saucers help! They catch excess water so roots can later draw it slowly up into the plant.
Excessive wilting stresses plants. When tomato leaves repeatedly wilt in late afternoon sun, move containers to a different location.
Watering is a double-edged sword. You need to water to produce healthy tomatoes. But watering leaches nutrients from containers. Tomatoes in pots can develop fully and produce a strong crop, but only with even watering and regular fertilizing. Be sure to fertilize your container tomatoes often to compensate for nutrient loss from watering.
Look out for blossom-end rot (BER) – blackened tomato bottoms! It’s caused by low calcium uptake associated with irregular watering. Regular watering helps. BER affects plants most readily early in the season when plants are young and have difficulty absorbing calcium needed for proper fruit development. Most potting mixes contain enough calcium. As plants mature, BER usually disappears. To prevent it, you can add lime or crushed egg shells to your potting mix when planting. Fast-acting lime will increase calcium uptake early in the season, too.