Inconsistent Watering

• Tomatoes often split not because the soil is too wet, but because the soil was too dry before it was watered. When tomatoes absorb a lot of water all at once, their skins stretch; too much water causes splitting. Watering regularly will help. Drip hoses for irrigation provide a regular source of water to outdoor tomatoes, which can minimized the stress of sudden under- or overwatering. Container-grown tomatoes should be watered only when the soil is dry an inch beneath the surface. If you will be out of town for a length of time, use a drip irrigation system with a timer or ask a neighbor to water your tomatoes to encourage regular growth.
  
  

Weather Conditions

• Temperature, sunlight, and overfertilizing can also cause skin damage to your tomatoes. Container-grown tomatoes can be moved if high temperatures or strong sunlight are harming the plants. Fertilize regularly, and do not overfertilize if you are late on your schedule.
  Being attentive to watering and to weather conditions is the best way to avoid splits in your tomatoes. If a heavy rain is coming or starting, pick the ripe tomatoes immediately. You probably won't be able to avoid splitting altogether, especially from rainstorms, but harvesting your tomatoes regularly can help minimize damage.
  
  

No Mulch

• Good mulching helps plants regulate their moisture and temperature levels during extremes. Mulch around your tomatoes as directed by the seed package or the tag on your starters. Using black plastic mulch during the spring can protect your tomatoes from unexpected cold and heat during their early growth period.