The climate in northern and central Europe has changed in recent decades. On average, the average annual temperature has increased by around three °C. In addition, temperatures below -15 °C are rarely reached in the temperate regions of Northern Europe. This change opens up completely new cultivation possibilities: Wine, for example, is no longer only cultivated in the classic areas, but new cultivation areas are even emerging in Denmark and Sweden. But does this also apply to lemons?
Classic lemon varieties are not hardy
Classic lemon varieties of the Citrus limon genus are not hardy in our latitudes and should be overwintered according to their needs. The danger is not only that the tree could freeze to death due to the frost that may occur. The weather is generally too wet and also too dark. Lemons ideally overwinter at an average temperature of around 10°C and with significantly more light than the winter sun is able to give them.
Hardy lemon varieties
However, there is a way out - as long as you do not value edible or tasty fruit. The bitter lemon, also known as the three-leaf orange (Citrus trifoliata or Poncirus trifoliata), originating from central and northern China, is the only citrus species that is deciduous in winter and frost-hardy down to temperatures of -25 °C. This pretty bush, which can grow up to three meters tall, can be planted out in the garden without hesitation. The bitter lemon is often used as a grafting medium, which in turn makes the grafted plant less sensitive to cold and wet conditions. However, their yellow-orange, hairy fruits are inedible due to the bitter substances they contain.
Other hardy citrus varieties
Crossbreeds or hybrids of the bitter lemon described often prove to be hardy, but only down to temperatures between minus eight and minus twelve °C. These are hybrids of orange and bitter lemon (citranges), tangerine and bitter lemon (citrandarines) and the so-called papedas (ichang). However, the fruits of these trees have a more or less tart-sour aroma. Basically, the more frost hardy the citrus variety, the less tasty the fruit.
Ichang Lemon
The Ichang Lemon is a very old Chinese hybrid of Citrus ichangernsis and Citrus maxima. The plant is frost hardy down to minus 10 °C. It forms a broad bush with large, pendulous leaves and shoots and large, white flowers. Its fruit resembles a plump lemon with a thick, soft peel. The flesh has a sour pomelo flavor with the slight bitterness of grapefruit.
tips and tricks
The millennia-old Japanese hybrid Yuzu is also frost hardy down to a temperature of minus 12 °C. It is a hybrid of ichang and tangerine that produces clementine-like fruits. The Satsuma tangerine is also quite frost hardy.