Market gardeners in Estonia are alarmed about the ongoing sub-zero nighttime temperatures, as nightfrost can damage many plants. Gardeners do however have experience from as recently as last spring, which also saw unusually low nighttime and morning temperatures for the time of year.
Forecasters are predicting frost overnight with ambient temperatures just a few centimeters above ground potentially dropping to as low as -8 degrees Celsius.
Ulvi Moor, head of the Department of Horticulture at the Tartu-based Estonian University of Life Sciences (Maaülikool) said: "Tomatoes, cucumbers, basil, and pumpkins are heat-loving plants, and they are already stressed by the current conditions.
"Temperatures below +12 degrees Celsius already cause them stress. So it is generally too early to plant them; this however depends on how well-insulated a greenhouse is," Moor went on. "Polycarbonate greenhouses and those with double plastic film retain heat somewhat better than glass greenhouses. But if the temperature drops to minus eight, there's a risk it could affect even those greenhouses," she went on.
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