Wrapping trees with protective trunk materials can cause more harm than good, said a New Mexico State University forest entomologist. The material is said to protect tree trunks from drastic changes in bark temperature, which can lead to sunscald and frost cracking. This is the same reason many fruit and nut tree trunks are painted with white latex paint.
Some people use the wrapping to protect trunks from drying winds.
ISA reports that in some cases so much moisture has been held under the wraps that trees actually grew roots along their trunks. Cain and Jim Freeman, urban forestry coordinator with the State Forestry Division, spent an afternoon in April unwrapping tree trunks covered by paper wrap. The trees had been planted 16 months earlier in Santa Fe. Despite a very dry winter, the paper wrap retained moisture against the bark of the trees. Cain said freezing and thawing appeared to have caused some bark injury and may have allowed entrance of disease fungi.