Sweet corn planted in Oklahoma should reach maturity by July or it won't pollinate well. Check the sweet corn seed packet or catalog to calculate days to maturity, usually 70 to 90 days, depending on the corn variety. It is best to plant sweet corn in Oklahoma by late April.
About this Author
Bobbie Brewer has been writing since 1990. Her work has appeared in publications and on Web sites including Garden Guides and Trails. Brewer is an international traveler, outdoors enthusiast and has been gardening since 1991. She has a Bachelor of Arts in English from California State University, Sacramento.