Your concern is understandable because citrus trees are regarded as subtropical plants, which means they're not particularly cold-hardy and are ... Southern Frost navel orange (Citrus x sinensis ...

The team of researchers found that a gene in Poncirus trifoliata, a hardy citrus relative, is what's behind the plant's ...

Grafting citrus onto trifoliate orange rootstock imparts added cold hardiness to the upper part of the tree — an important reason we plant grafted citrus trees. They are more likely to survive ...