Rainwater is the best hydration source for tomato plants. You can collect and save rainwater in a barrel to water the plants. Tomato plants require one to two inches of water a week, according to the University of Missouri Extension.
About this Author
Suzie Faloon is a freelance writer who has written online content for Demand Studios and Associated Content. As a professional crafter and floral designer, Faloon owned a florist business for nearly 25 years. She completed the Institute of Children's Literature course in 1988.