Researchers at A&M insist that ball moss will not harm your trees and I tend to believe them. If you notice, ball moss doesn’t need a living organism to grow on. You may have seen it grow on insulated wires or on the edge of roofs, etc. Ball moss is not a parasite, it simply “perches” itself on trees. It is, however, very unsightly and can add more surface area for wind, rain, ice and snow and therefore become a factor for weather-related damage.