How much water does a tomato need? I have read the articles that discuss frequency and time of day but ignore quantity. I have located the university papers that discuss irrigation and transpiration and are written in Martian. I am just trying to water 7 outdoor tomato plants for absolutely optimum results. Can you help me?
Water Quantity for Tomatoes
Certified GKH Gardening Expert
There is no one set amount for this. There are dozens of factors that can influence how much water a tomato plant needs at any given time. These factors can include age of plant, size of plant, type of soil, current temperatures and humidity, state of fruit and amount of fruit as well as weekly rainfall.
A general baseline is considered to be 2" of water a week for a plant in the ground (more often for container plants). Due to all of the factors above, this amount may be too much or too little for your tomato plant. Instead, it would be wise to depend on a water gauge or an indicator plant to tell when you need to water your tomatoes. Impatiens make a good indicator plant to put near your tomatoes as impatiens wilt immediately when they have too little water, thus indicating that the tomatoes also need water.