According to popular belief, the Ice Saints days are a period of three critical days in May during which the yard is exposed to the risks of cold and heavy nighttime frosts. Once these three days are over, you no longer need to worry about frost. So what are the Ice Saints days? What frost-tolerant plants can be planted beforehand? How can you protect your plants?
The Ice Saints days, an established tradition
The Ice Saints days, which characterize a specific three-day climatological period from May 11 to 13 are based on a popular European belief dating back to the Middle Ages. They represent three saints— Saint Mamertus (May 11), Saint Pancras (May 12) and Saint Servatius (May 13)—all of whom protect crops against the risk of late frosts. Medieval lore states that gardeners should beware of frost until after these days have passed . Today, these three saints have been replaced by Saint Estelle, Saint Achille and Saint Rolande respectively. And as per the ancient belief, these three days mark the last of the winter frosts followed by the safety of warmer weather.
If you want to play it safe before the Ice Saints days, plant hardy perennials, trees and shrubs which are frost tolerant. Lots of plants are resistant to the cold and these are referred to as frost tolerant.
Suitable shrubs include the essential boxwood, heather, flowering cherry known for its spectacular blooms, variegated holly, forsythia with its clusters of golden yellow flowers, and cotoneaster.
There’s also a wide choice of flowers: pansies, primroses, catnip, rugosa roses, hellebores and hardy geraniums... all varieties to bring beauty and color to your yard!
Solutions to protect plants from late frosts
If you’re worried about a drop in temperature and frosts that could occur up until the end of May, use fleece to protect your pots and planters from winter conditions. It will protect the roots of your young outdoor specimens. For young plants already in the ground, mulch (straw, dead leaves, etc.) is a good option. Vegetables should be under a cloche or in a mini greenhouse if they’re in seed trays; and the most sensitive plants should be brought indoors if possible and placed in a well-lit room that doesn’t get too hot. Top tip: Never water your plants when the temperature drops.
Should we really pay attention to the Ice Saints days?
Even if you’re not convinced by the Ice Saints, it’s advisable to check out the weather conditions before and during this period if you want to plant anything out. And bear in mind that temperatures at this time of year can be very changeable.
May 11, 12 and 13 are linked to the lunar cycle and fall into the “pink moon” period that ends on May 15 this year. Young shoots are sensitive to this lunar period where the temperature differences between day and night can exceed 10° and therefore freeze (or “fry,” from the pinky-red color of the moon) the roots.
The risk of late frosts in France is less south of the Loire than it is north, so it’s important to take account of this in your planting schedule.
It takes longer for the earth to warm up after a long, cold winter so you might want to consider planting your more sensitive specimens (tomatoes or courgettes for example) after the Ice Saints days. Or, if you do plant them out, give them a helping hand by aerating the soil with a claw or fork so that it warms up faster.
Note: According to Météo France, the French weather service, the last time the Ice Saints days lived up to their name was 2010!