It's been a good year so far for moss in western Oregon. That is, good for moss but not so much for homeowners. Mossy roofs can be a problem, as can slippery patios, decks and walkways.
For people concerned about mossy roofs, OSU Extension Service horticulturist Ross Penhallegon recommends sweeping off as much moss as possible and trimming any overhanging tree branches that block sunlight and air from the roof's surface. To keep moss from returning, you can apply commercial moss removers, which are best applied during a dry spell during the fall, winter and spring, when moss is actively growing, Penhallegon says. Moss removers that contain zinc or iron sulfate can be toxic to plants, and need to be applied directly to the problem areas. He cautions against using table salt. Installing zinc or copper strips on the roof also can help with prevention.
Moss on patios and paths can be treated the same way: first scraping off as much as possible, then applying moss removers (the same kind as for roofs) if necessary.
Moss on trees, though, is another story. There's no reason to remove it, Penhallegon says. Same goes for lichen and algae.
Want more? Read the Extension Service's
-- Homes & Gardens staff
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