Moss Flinging
Appreciating Moss - in the Woods
I sit here listening to the buzzing whirr of the power sprayer on the roof. With each zing and buzz, a little more moss is dislodged. My husband is out there rigged up in his climbing harness and tied via climbing rope to a big ash tree on the opposite side of the A-frame house. The rope comes over the peak and holds him in a rappelling position as the pitch of the roof makes it impossible to stand on. The power sprayer sits atop scaffolding erected on the front porch. Two lengths of hose and extension cord help it reach the top of the fourth level. Quite the operation; not something we want to do every year. As I watch the many bits and pieces of moss get flung off, I think about why the shingles on our shady north side are so conducive to the growth of moss.
Moss is a non-vascular plant, meaning it lacks the vessels for transport of water and nutrients. Therefore, by necessity moss stays small and grows close to or within a ready source of water. So shady places, damp places, near streams and water sources, wooded areas are all likely places for moss to inhabit. Acidic soils and surfaces are its preference.
Moss has a rather involved life cycle, involving a haploid stage and a diploid stage, so I’m not going to get much into it here. However, the spores resulting from its reproductive cycle are masters at dispersion. They can ride the wind or get tossed by rain and be flung far and wide. Not only that, the spores can start growing pretty much anywhere they land, given enough moisture. Wood, brick, coarse rock surfaces, soil, cracks between cement and asphalt and yes, roofing or anything that is porous or moisture retentive or has a rough surface are subject to moss growth. Once established, moss is super great at retaining water and which not only greatly reduces the lifespan of roofing, but aids in breaking down solid rock.
Getting rid of moss where you don’t want it takes eliminating one of its requirements for survival. Depriving the area of moisture by allowing more direct sun to hit the surface or by creating a drainage system will help. Heavy traffic will also eventually discourage it. Changing the pH of the substrate will also do the trick. This is the logical solution for our roof, as I don’t want to eliminate the beautiful big oak tree on the north side of our house that is the primary shade producer. Strips of copper installed within the rows of shingles on your roof do a great job. As rain falls on the exposed copper and rolls down the roof, it makes for very unsuitable conditions for moss or algae to grow. Any homeowner advice store or website will have more on this.
Aside from my roof, I love moss. To find a big bed of cushy moss on a hike is an invitation for a rest and maybe a quickie nap. Sticking your hand in a thick matt is simply luxurious. With about 12,000 species of moss growing in nooks and crannies all over the world, I think it goes unappreciated and is vastly overshadowed by those showy flowering plants. So, next time you are out and about in your own backyard, bend down, or look up at your rooftop, and take notice of this ubiquitous little survivor.