When Is Best Time to Water Tomato Plants?

Early Morning

• Once a seed sprouts, water becomes essential; if allowed to dry out, the seedling or plant will die. The early morning typically consists of a higher humidity and lower temperatures, both factors that reduce or limit the evaporation rate. Watering in the early morning before the sun dries the dew, increases water absorption by tomato plants. Water applied during this time experiences less evaporation.

Late Evening

• Plants retain more water when given longer opportunities to absorb available moisture. Late in the evening after the sun has set is the best time to water garden plants. Under normal weather conditions, as evening approaches, the humidity begins to decrease, reducing the evaporation rate. The extra hours of darkness and lower temperatures provide a longer period of absorption than any other time. Watering during this time will ensure more moisture permeates the soil and is absorbed by plants.

Factors that Affect Water Requirements

• Generally it's not a good idea to water tomato plants on a regular basis unless conditions warrant. There are many factors that when present, affect the plant's watering needs. Unseasonably high temperatures increase a tomato plant's need for water; just as an unusually long, rainy period decreases the need to water. Exceptionally cool weather prompts less evaporation and regular watering during this period can cause the tomato plant to rot. Other factors that can affect the watering needs of tomato plants include the soil's ability to hold moisture, excessive wind, and the growth stage of the plant.

Watering Tips

• Know the signs of tomato plants needing water. Curled, wilted, or yellow leaves don't necessarily indicate a thirsty plant. These are also symptoms of common diseases and other issues that affect tomato plants. During the summer when the days are hot, plants commonly wilt at the end of the day and doesn't necessarily indicate watering is in order. Plants that do not rebound overnight do need to be revived. Be cautious with night watering as every climate is different. Night may be an optimal time to water for some and an open invitation to disease and fungus for others.