Follow label instructions for mixing and using all spray products. Be aware that these sprays can cause discoloration on house paint, so use caution when spraying near buildings. The dormant season from late November through early March is the best time to spray. The chemical must contact the lichens and mosses to be effective. Areas not covered will not be controlled.
Hazelnut trees are the only exception to spraying during the winter.
They should not be sprayed during the pollination process, which could be anytime from early December through February.