Citrus and frost
The vast majority of the citrus sold do not tolerate frost, but some can. One is, for example, Citrus Trifoliata, also known as the hardy orange. It can withstand down to 20 degrees frost if it is not too exposed and otherwise have been well protected in its infancy. The fruits do not look like lemons, but smaller oranges, and they are almost inedible. Other sorts that can withstand frost are the citrus glauca and kumquat, fortunella margarita, citrus japonica and citrus cavaleriei, which can withstand down to minus 12 degrees. The citrus reticulata can withstand minus 14 degrees.
Citrus should be in a cool, frost-free place with lots of light in winter. The tree needs just little water, maybe at the most every 14 days, depending on the sun and heat. With several layers of bubble wrap, you may be able to keep a temperature above freezing point.
Om Lars Lund
Danish horticulturist and journalist
Lars Lund has for many years engaged in the garden and greenhouse. Lars has published many books about greenhouses, and he has participated in many Danish horticultural TV shows. He is a walking garden encyclopaedia, and he has answers for most basic cultivation questions – also the more ambitious ones.