How Moss Works

Moss lovers, cover your ears. It's time to talk about some of the problems moss can pose and what can be done to, well, kill it.

There are many reasons, both practical and aesthetic, why people choose to get rid of moss. If it's growing in your lawn, eradication isn't a necessity; moss won't overtake established grass and generally grows in shady, acidic soil that isn't good for turf anyway. Those who prefer fence-to-fence sod, however, may see it as an eyesore and choose to kill it. Moss isn't likely to cause much damage to brick or concrete, either, but moss on a sidewalk can be slippery and may need to be removed for safety reasons.

Rooftop moss can be a bit more problematic. Sure, moss on your roof will make your house look like something out of "The Lord of the Rings," but roofing professionals insist that the plant can be a real cause for concern. One issue is that moss's tiny rootlike rhizoids can grow into small cracks in the roofing material, causing the roof to deteriorate. Moss may also grow under shingles, lifting and loosening them from the surface. Finally, moss can hold moisture on your roof, creating a habitat for decay-causing organisms like fungi. All of these issues have the potential to cause leaks and send water into your otherwise dry home.

So how do you get rid of moss? For lawns, pesticides can be an effective way of killing the plant, though they may be toxic and should be used sparingly. A better way to attack the moss is to treat the root of the problem. Make sure the area drains well, cut back overhanging branches and decrease the soil acidity with lime to discourage future growth. Moss on sidewalks and bricks can simply be scraped off with a shovel or hoe, but if it grows back it may have to be treated chemically. Before using any moss-killing product, test it in an inconspicuous place first to ensure it won't stain the surface you're treating.

And then there's your roof. Just like the lawn, your roof is best treated by addressing the underlying conditions that cause moss growth. Any plant matter resting on its surface can collect moisture and allow moss to take hold. Trim back overhanging tree branches and clear off leaves, pine needles and twigs. If this doesn't completely eliminate the problem, chemicals similar to those used in your yard are available for the treatment of roofs. Zinc is also a very effective deterrent to moss growth; strips made of this metal can be installed along the roof peak or beneath the shingles.