However, an olive tree can withstand frost overnight, he can get a shock if it is a prolonged period of frost. One tree comes through with no problems, others will already drop its leaves. But an olive does not die quickly. Especially the bigger ones and the ones that are encased come right through. If the tree has lost all the leaves the tree should be examined in the spring where the living part is still in the twigs. Only the tops are often frozen. Only this should then be cut off. Make a small scratch with your fingernail on the bark, you can easily see if the branch is alive, if you spot green it is ok if it is not green but brown and dry the twig is dead. The humidity of the soil is very important keep an eye on the olive tree and fertilize properly. You can buy a nutrition package
Then with a new period of sun the olive tree will again form new leaves. It is a slow grower, and he will do about two months to recover from the winter.