When Should Tomato Plants Be Watered in Hot Weather?

Using the proper watering technique improves tomato production.

In hot weather, tomatoes should be watered in the morning hours. Tomato plants require 1 inch to 2 inches of water per week if planted in good soil. It is better to deeply water tomato plants once or twice weekly than to water lightly each day. Proper irrigation techniques will ensure water is absorbed by tomato plants and not wasted through evaporation or run-off.

Soil Type

Tomato plants grown in hot weather require different amounts of water depending on soil type. Sandy soils may require additional water and clay soils may require less water than tomatoes grown in garden loam. Wilting and curling leaves indicate tomato plants are not absorbing adequate amounts of water. Flat, drooping leaves indicate plants are over watered. The soil is adequately irrigated when it is moist 6 inches below the surface at the time of irrigation. Amend sandy and clay soils with compost to improve the water holding capacity of sandy and clay soils.

Drip Irrigation

Tomato plants grown in hot weather require less water when irrigated with drip, or trickle, irrigation. Because drip irrigation applies water directly to the base of the plants at a rate plants can absorb, less water is lost to run-off and evaporation. When using drip irrigation, water tomatoes for three hours, two times weekly.

Mulch

Mulched tomato plants require less frequent irrigation than unprotected plants in hot weather. Organic mulches, such as straw and leaves, cool the soil, reduce evaporation and increases the water holding capacity of soil. Apply 3 inches to 6 inches of mulch in early summer when temperatures begin to rise.

Weeds

Tomato plants grown in hot weather require more frequent irrigation if weeds are present in the garden. Weeds compete with plants for root space and rob tomatoes of moisture and nutrients. Nutrient deficient tomato plants cannot absorb water as readily as healthy plants. For best water uptake, remove weeds from the garden and mulch to prevent regrowth.

References

• Clemson Cooperative Extension; Tomato; Marjan Kluepfel and Robert J. Dufault; April 2003
• Texas A&M Extension; Efficient Use of Water in the Garden and Landscape; Jerry Parson et al;

Resources

• University of Florida IFAS Extension; Tomatoes in the Florida Garden; James M. Stephens; April 1994