Pathogens and Pests
More often than not, a tree’s bark will crack, allowing insects to creep inside. Once that happens, fungi and bacteria will feed on the tree’s innards, stunting its growth and eventually killing it.
As a result, whitewashing mixtures contain three parts water and one part interior latex paint. The paint itself prevents insects from crawling up the tree and entering inside through the cracks.
Other whitewashing formulas use hydrated lime with water and salt or kaolin. As a matter of fact, people use kaolin to protect fruits from pests because it can be washed pretty easily before consumption.