All citrus trees are tropical to sub tropical in their natural environments, which means they are not tolerant of cold weather, according to the United Nations Conference on Trade and Development. Citrus trees are all evergreen and bear fruit within two to three years, and they need well-drained soil in which to grow. The fruit on citrus trees usually takes six months to ripen. Citrus trees are sensitive to frosts of any kind and you must protect the trees from the frosts by covering them up.
Water the ground around the citrus tree before the frost and clear the area of any mulch or weeds.
Wrap the citrus tree's trunk in insulating material like cardboard or fiberglass, from the base of the tree all the way up to the branches, and tie it in place with the rope, advises the University of California.
Wrap each of the large branches in cardboard or fiberglass as well, and tie it in place with the rope.
Cover the entire canopy of the citrus tree with a large blanket and a plastic tarp, both of which should reach the ground around the tree. Tie them in place if needed.
Remove the blanket and plastic tarp once the temperatures reach above 30 degrees F.