According to Iowa State University Extension, the last practical date to plant your tomatoes in Iowa is about June 20. If you plant too late, the fruit will not have time to ripen before the first frost.
About this Author
Aileen Clarkson has been an award-winning editor and reporter for more than 20 years, earning three awards from the Society of Professional Journalists. She has worked for several newspapers, including "The Washington Post" and "The Charlotte Observer." Clarkson earned a Bachelor of Arts in journalism from the University of Florida.