• When tomatoes should be watered.Image by Flickr.com, courtesy of salman al-salman
  
  

Requirements

• Each tomato plant requires two quarts of water per day during the growing season, and they need up to four quarts once fruits have set, according to The University of Missouri's Division of Plant Sciences.
  
  

Misconceptions

• It's a widely held belief among gardeners that watering tomato plants at night spreads diseases. Dr. Steve Reiners of the Department of Horticultural Sciences at Cornell University explains that the wet foliage causes diseases to spread, not necessarily the time plants are watered.
  
  

Considerations

• Overhead watering systems--such as sprinklers or spray hoses--wet the foliage, making it more susceptible to the spread of bacteria and fungi. Plants take in water through the roots; there is no need to wet the leaves or fruits.
  
  

Time Frame

• With overhead watering, early morning is the ideal time to water so plants can dry in the sunlight. Watering can be successfully done at night if foliage remains dry. Demesne.info recommends keeping foliage dry by watering the base of the plants.
  
  

Prevention/Solution

• A drip irrigation system, such as a soaking hose, should be used for night watering. These systems water slowly at the base of the plant, sending water directly to the roots. They keep foliage dry.