Statues of saints line the Charles Bridge in Prague, the capital of the Czech Republic. A Czech legend warns against planting tender crops too early, in case of a late frost. (photo/Cindy Hadish)

When temperatures reach the 70s in April, it can be tempting to start a gardening frenzy, but in Iowa, it’s best to heed a warning brought here by immigrants.

Known under various names, including the Three Frozen Kings, the three icemen – tři ledovi muži – or Three Ice Saints, Three Frozen Men or Three Iron Men, the Czech legend warns against planting tender crops too early in case of a late frost.

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According to the legend, the three kings or saints – Pankrac on May 12, Servac on May 13 and Bonifac on May 14 – were frozen when temperatures dropped while they were fishing at sea. On May 15, St. Zofie came along with a kettle of hot water to thaw out the three frozen kings.

The legend serves as a warning to protect tender plants against a possible late frost.

Iowa’s climate is similar to the Czech immigrants’ homeland, so many settled in the state to pursue farming and other occupations.

While many vegetables, such as peas, kale and lettuce, can be planted sooner in Iowa, wait until May 15 to plant your tomatoes, peppers and other tender vegetables and flowers outside, or at least provide them with protection in case overnight temperatures drop below freezing.

Perennials can be planted before the last average frost date, and it’s often even preferable before the heat of summer hits.

Learn more about Czech events in Iowa.