Some people whitewash just because they like the looks of it. You can whip up a batch quickly with material readily available from any local hardware or home improvement retailer.
This is our first year to paint our trees...even our young fruit trees are now painted. We're mere copycats, but doing so, we'll be able to see if this is just a mythical practice or whether it is really beneficial. Time will tell.
Painting fruit tree trunks with a mixture of lime and water is used most often to protect the bark of delicate trees from sun damage. The lime paint reflects the sun's heat, creating a hot surface insects will not cross. Lime paint applied to the bark of a fruit tree usually lasts for one to two growing seasons before it needs to be reapplied.
What are your thoughts about this practice?