(Radio Iowa) – Iowa’s temperatures this spring are rollercoastering, warming into the 80s one day and spiraling into the 30s the next, making it a challenge for farmers to launch into their spring planting. Iowa State University Extension field agronomist Meaghan Anderson says the optimum planting window for Iowa corn has been April 11th to May 18th, but growers need to pay attention to the weather before — and after — planting.

“The date on the calendar, at least in Iowa, is not right quite yet,” Anderson says. “To totally eliminate any risk as far as maybe a frost issue, or just cool temperature effects on our crops after they’ve been put in the ground, so there’s always that risk.” Although having a soil temperature of at least 50 degrees at planting is important, Anderson says that soil temp should remain at 50 degrees or higher — after — planting to prevent injury to the seed.

“We want the soil temps to be about 50 degrees and then we want to make sure the forecast would allow it to be trending warmer after we’re planting,” Anderson says. “That allows some stability in temperature to make sure the crop’s not going to be exposed to any especially cold temperatures.” For those who decide to plant early, she says to keep in mind that crop insurance will not cover a replant until April 11th.

“If a farmer would be relying on the crop insurance to help us replant crops,” she says, “they’ll want to make sure they’re waiting until that replant has kicked in with the crop insurance before they’re planting the first time.” Early planting for soybeans is anytime between April 11th and April 25th. Anderson says growers wanting soil temperature information can access the Iowa Environmental Mesonet at: https://mesonet.agron.iastate.edu/