Why are leaves on my tomato plant turning yellow or brown?

There are yellow and brown leaves on the bottom of this tomato plant, but that’s normal. Photo by Connie Oswald Stofko by Connie Oswald Stofko The leaves on the bottom of my tomato plants are turning yellow, then brown. Don’t worry; it’s normal, says Jen Weber, vice president and manager of Mike Weber Greenhouses at 42 French Rd., West Seneca. “That’s what happens when the plant starts making tomatoes,” she said. “It’s better to have an ugly plant with lots…