My tomatoes are starting to split. I live in the valley between high and low deserts. We are hot but not like Phoenix. It can get 103 or more degrees in summer, usually mid to high 90s. Our spring bounced from cold to hot frequently but has stabilized. I have never been able to figure out frequency and length of time. I have a gauge that I can set times and make flow fast or slow. The garden is wood mulched. I just read it said "once a week about two inches." That doesn't seem right for here and, also, how do I measure "inches" in an 80sq foot spot w/bell peppers too? Thank you so much!
Watering Amount and Frequency
Certified GKH Gardening Expert
The splitting of your tomatoes is is called cracking and is common with tomatoes that have uneven watering. This article will help: https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-cracking.htm
There is no one set amount for watering, as 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.