Whitewash is applied to trees, especially fruit trees, to prevent sun scald. Most often only the lower trunk is painted. In Poland painting the whole trunk is also said to help keep the body of the tree cool in late winter and early spring months and hence help prevent fruit trees from blooming too soon, i.e. when warm sunny days could promote rapid tree warming, rising sap and bloom and intermittent frosty nights could damage outer tree rings and destroy the young buds and blossoms.

Both summer sunburn and winter sun scald can cause the tree’s bark to crack or die, resulting in additional stress which is compounded by insects and parasites that enter the barkless wood, an invasion that will ultimately shorten the tree’s life. Tree paint or whitewash protects against this.