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First sign of spring might be pesky moss

Moss is coming to life and could soon overtake the lawn if steps aren’t taken to control it.
Moss is coming to life and could soon overtake the lawn if steps aren’t taken to control it.

Slowly but surely life is returning to the landscape. But that green appearing in the lawn may be an unwelcome resident. Moss is often the first thing to green up.

It appears for a good reason though. It is an indicator of poor growing conditions such as low soil fertility, high soil acidity, heavy shade, improper watering practices, diseased grass or poorly drained or compacted soil.

There is no quick fix to remove moss. In the short term, several types of moss killers are available that will kill existing patches for a short period. Raking it out of the lawn will remove the top of the plants but will leave enough fragments that it will grow back quickly. Even the moss killers can be a problem; the iron phosphate-based ones will stain walks, siding and clothes a rusty red.

The long-term fix involves changing the environment so the plants you want will grow properly. Start by checking your watering practices. Moss thrives in damp places other plants don’t like. Check your sprinkler system and adjust timer settings or spray patterns to reduce overwatering and ponding. Reroute downspouts and other sources of runoff to reduce ponding.

Compacted, poorly fertilized areas don’t allow air and nutrients to reach the root zones. Aerate mossy areas in the spring and fall to help break up compacted soil surface layers. Add an inch or two of good quality compost each year to the area to improve fertility and provide new soil for the grass to grow in. Do a simple soil test to determine pH and nutrient levels and then apply fertilizer at the appropriate rate.

Let in the light. Remove overhanging branches and shrubs to let in more light. Kentucky bluegrass does not do well in shade and will thin out, giving moss an opening to move in. If the area is still too shady for bluegrass, try planting a tall fescue seed that is much more tolerant of shade.

Why is moss so persistent?

First, moss has been around for millions of years and survived everything nature has thrown its way, including numerous extinction events and cycles of climate change. Its simple biology has allowed it to adapt to environments from the Arctic to the tropics and even on the edge of hot springs. Your lawn is a little piece of paradise for it.

Second, moss has several methods of reproduction. It sends out spores (think seeds only simpler) that easily travel to new locations; it sends out shoots in the spring from parent plants and finally by fragments that break off the main plant and find their way to new locations.

Tired of dealing with it? Consider letting the moss become an element in your landscape. Japanese and Chinese garden designers have made an art out of incorporating it into landscape. A walk through the Japanese Garden at Manito Park will demonstrate its versatility and simple beauty.

Pat Munts has gardened in the Spokane Valley for more than 35 years. She can be reached at pat@