Natalie Hoidal and Marissa Schuh , Extension Educators, University of Minnesota Extension. Originally published 2021, updated 2025. Choosing varieties & when to plant Consistent sweet corn emergence is more likely when seeds are planted when the soil is warm enough. Photo: Marissa Schuh, University of Minnesota Extension. While regular field corn is planted in late April or early May, sweet corn can be planted May through July. Many vegetable growers aim to grow the earliest vegetables possible to get a leg up at farmers markets, but sweet corn germination is very dependent on soil temperatures. For optimal germination, wait until the soil is: 55°F at an absolute minimum, 60-65°F for supersweet varieties The Growing Sweet Corn in Home Gardens page has a list of sweet corn varieties and the optimal germination temperature for each. Super sweet corn (sh2 type) usually needs to be planted later (in warmer soil) than synergistic or sugar enhanced (SE types). If your v...
