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.

"For open fields, there aren't many options. Outdoor 'vegetable candles' is one possibility. For instance, I plan to place a candle under my blooming sweet cherry tree. I'll be honest, I had never had to do this before. This is a large outdoor candle that burns for 10 hours. I just can't bear to see my cherry tree, now in full bloom, suffering. How many degrees it actually staves off or how effective it will be, I don't know yet as there's no definitive scientific proof," Moor went on.

Sub-zero temperatures pose a significant risk to early blossoms such as those on cherry trees.

A double layer of frost cloth is also an option for outdoor plants, though this should be place on supports above the plants, rather than being draped over them, Moor said.

In any case, Moor recalled that around this time last year there were nights with temperatures below zero where even strawberries which were sheltered under frost cloth froze.

Greenhouses should also be kept closed during the day, she added.

As for potatoes, Moor noted that they are not at risk from the frost as they have not yet sprouted and are buried in the soil.

That does not mean that all will be plain sailing here, either, she noted.

"Last year, the issue occurred in early June when the potato tubers were pretty big. Any potatoes which have sprouted so far would die, but new ones will grow because the portion under the soil remains intact. The yield will just be smaller that's all. But for home gardeners, this should not be an issue yet. Their potatoes won't have sprouted yet," Moor concluded.

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