Spring at risk: overnight frosts in Luxembourg jeopardise fruit harvest

Chilly nights with temperatures down to -2...-3°C have been recorded across Luxembourg for several days in a row, causing concern for farmers and winemakers. This is a critical period: trees and crops are in the active phase of flowering and growth and are therefore extremely vulnerable to the cold.

"Even one hour below -2°C can have serious consequences," warns Jean-Claude Muller, president of the Luxembourg Horticultural Association. Last year, late frosts already dealt a significant blow: plums, cherries and pears were affected. Depending on the flowering stage, the critical temperature threshold varies: up to -4°C, the tree can survive without flowers, but at -1.5°C with pollinated flowers, irreversible damage can begin.

The vineyards are not yet fully "awake", which gives a certain respite. "For the moment, the vineyards are still in the dormant phase, and that saves us," explains Antoine Clasen, General Manager of Caves Bernard Massard, in a comment to L'Essentiel. But he does not hide his concern: "Last year we lost 30 per cent of our harvest due to frosts, and in some areas we lost 100 per cent". Historically, frosts have occurred in the region even in early May, such as on 5 May 2019 - which is why winemakers continue to be wary of the forecast until mid-May.

The frost has also affected the vegetable growers' decision. "We are not planting anything outdoors yet," says Sandrine Pingeon, a farmer from Munsbach. All the young plants are in greenhouses - and even there they are covered with extra protective films. The reason for this is the drastic differences between day and night temperatures, which can kill seedlings literally overnight.

Premature warming followed by frost is a worrying climatic trend in recent years. Farmers have been living between hope and fear for a number of seasons now, when every flower is a potential fruit and every frost is a step towards loss.