When is the best time of year to apply moss killer. It is so hard to get rid of on our aggregate patio surface.
Yamhill County Oregon moss
Thank you for your question. Since the environmental conditions of your patio are favorable to moss, they are going to continue to grow there, regardless of your efforts. There are both physical and chemical methods to keep it at a 'reasonable' level, some of which are more environmentally friendly than others. The time and frequency for application of each differs, so reading the product label and following it strictly is the best advice. Here is an excerpt from an OSU Extension publication with the possibilities: http://bryophytes.science.oregonstate.edu/page24.htm
Hope this is helpful. Good luck!