How many trees do you have? I only have a few so I go to Walmart and buy one of their little sample containers of white latex with a cheap brush, costs less than $5. Take this home and mix it 50/50 paint to water. Apply this to the trunk and up on the thicker limbs. It does seem to help on trees larger than an inch or two. I also live along the Rockies and have had sun scald on unprotected trees. I should also mention that all of the orchards around here do paint their trunks so it must have some benefit.

We paint ours here in AZ and no more trunk splinting. We get sun scald in the winter when the sun is low in the sky and trees have no leaves.

Be sure to get the plain latex; some have anti-microbial chemicals in them and you do not want that.

Yku may find much reduced rodent activity, too. And borers.