While the growing season is still weeks away in Iowa, a season that once sustained the state’s residents is nearing an end. Cedar Rapids Naturalist Janet Aiels says the maple syrup season will come to an end as the weather continues to warm. Aiels says the season depends on freezing nights and warmer days to get the sap flowing.She says in some years, the season is only two weeks long, while in other years it’s six to eight weeks. Aiels says there were good sap flows in January, then it got cold and the trees shut down, and then it warmed up again and the sap flowed again. Aiels says maple syrup was one of the first substances harvested for food in Iowa.She says maple syrup was used as a main staple in the diet of the Native Americans who first lived in Iowa. She says white settlers learned the technique and it became important in their diet, too. Aiels says maple syruping is done mainly as a hobby today. It’s relatively easy: just drill a hole in a maple tree, stick in a hollow tube called a spile to catch the sap.Ironically, what we know as maple syrup today is mostly made from what’s become one of Iowa’s top crops.Much of the syrup we use today is actually corn syrup flavored with maple syrup. Aiels works at the Indian Creek Nature Center in Cedar Rapids, where they make maple syrup each year for educational tours.