When tomato plant flowers turn brown, the likely culprit is blossom-end rot. You can control blossom-end rot, which causes browning of tomato blossoms and fruit at the blossom end, by maintaining adequate calcium and moisture during fruit development.
About the Author
Kelli Bingham is a freelance writer with nearly a decade of experience in the field. Her works have been published in publications including eHow. She is currently pursuing a degree in business.