Radishes and other vegetables are sold at a farmers market in the Czech Republic. A Czech gardening legend warns against planting some vegetables too early in the spring. (photo/Cindy Hadish)

Gardeners who gave into temptation after multiple days of summerlike weather in mid-April would have done well to heed a Czech gardening legend.

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.

A string of record or near-record highs in the 80s across Iowa this past week prompted some gardeners to jump start the season, but with an abrupt plummet in temperatures this weekend and predicted wind chills in the 20s, some of that early planting was likely too soon.

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.

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

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

Related: Good Friday potato planting lore