One of my students posed the question, “Why does tradition suggest that we should plant our seed potatoes on Good Friday?” Yes, my student stumped me and motivated me to research the origins of this advice.

The answer lies in the global history of food crops. Native to the mountains of Peru, the potato was grown by ancient peoples predating the Inca. Spanish conquistadors arrived in South America in 1532 in search of treasure. Instead, they encountered the humble potato and brought tubers to Spain in the late 1500s.

Initially, potatoes were viewed with great suspicion in Europe due to their origin and their familial resemblance to poisonous nightshade. Potatoes are so closely related to nightshade that they are grouped in the same genus and share traits such as toxicity. Modern society should pay homage to the ancient peoples who experimented and discovered that potato leaves, flowers and fruit are toxic, but the tuber is good for eating. I’m sure mistakes were made. Even the tuber can turn green and accumulate toxic chemicals when exposed to sunlight. This is why we mound soil around the growing plants and abstain from eating green potatoes.

Europeans first fed potatoes to livestock but eventually learned to eat and even enjoy this nutritious tuber. Even so, initial suspicions were hard to put to rest.

The Good Friday planting tradition is thought to have originated in Ireland. Fearing that potatoes were unholy because they are not listed in the Bible, the tubers were redeemed by planting on Good Friday after sprinkling generous amounts of holy water on the soil. Other traditions suggest that working people planted their gardens on Good Friday because it was their first day off in spring or because the holiday aligned with a favorable moon phase.

While this planting tradition may be harmless in southern states, Good Friday planting can be risky for northern states. The Easter holiday fluctuates with the lunar cycle and can occur as early as March 22 or as late as April 25, a vast range of 34 days. This year, Easter falls on April 20.

The better practice is to consider the average last freeze date as well as soil temperature and saturation. The general recommendation is to plant two weeks before the average last spring freeze date. Potatoes can survive a light freeze but will be damaged by a hard freeze of 28 degrees Fahrenheit or lower.

Soil temperatures are equally important. To ensure good shoot emergence, plant when soil temperatures are above 45 degrees Fahrenheit. A probe-style thermometer can be used or alternatively consult the North Dakota Agricultural Weather Network for average soil temperatures around the region.

To prevent rotting, do not plant when the soil is wet. If you insert your shovel in the soil and mud sticks to it, your better bet is to wait until the soil dries.

Finally, start off right by purchasing certified seed potatoes that are disease-free. Happy Easter!