How Late in the Spring Can You Plant Sweet Corn in Oklahoma?

Harvest Period

• Corn growers in Oklahoma can harvest sweet corn during the time between early June and mid-July. Crops that were planted too late and would have matured after mid-July are not likely to grow well.

Last Planting Date

• The last planting date depends on the variety of sweet corn being planted. For example, a variety that takes approximately 80 days to mature should not be planted after April 25, whereas a variety that takes only 70 days to mature can be planted as late as May 5 and still have time to mature before mid-July heat.

First Planting Date

• Sweet corn requires warm weather and soil temperatures of at least 50 degrees Fahrenheit to germinate. Generally, sweet corn should not be planted until at least 10 days after the average last frost. In Oklahoma, corn should be planted after April 10, because the last frost is usually around April 1.