How to Kill Lawn Moss and Keep It Gone

Controlling moss can seem like an uphill battle once it gets established in your lawn, but effective control may be simpler than you think. Reclaiming your lawn involves dealing with existing lawn moss and correcting the conditions that invite it to grow.

To remove lawn moss from your yard and enjoy thick, green grass, follow these basics:

  • Understanding Lawn Moss
  • Controlling Existing Lawn Moss
  • Preventing Future Lawn Moss

Understanding Lawn Moss

Successful moss control starts with understanding that moss isn't like other unwelcome lawn "weeds." Mosses date back to prehistoric times, and they haven't changed much through the years. These primitive plants don't process water and nutrients the same way more advanced plants do. As a result, normal weed killers won't kill mosses. Even powerful herbicides designed to kill all plant types fail to kill moss or prevent its return.

Though it seems like mosses force lawn grasses out, the underlying truth is simpler. Grasses struggle in shady areas with acidic, overly moist or compacted soil. Mosses flourish in those same conditions. Where grasses fail, mosses find ideal growing conditions. When lawn conditions support healthy, vigorous grass growth, mosses rarely appear.

Mosses flourish in moist, shady, acidic soil.

Controlling Existing Lawn Moss

The best time to treat moss is when it's actively growing. That typically happens during the fall rains, warm winter rains and early spring. Lawn mosses don't need much light or nutrition to live, but moisture is critical – both in its surroundings and in the plant itself.

Moss control products based on iron and naturally occurring iron substances, such as ferrous sulfate, are highly effective at killing lawn moss by drawing out moisture so mosses dry up, turn black and die. The Lilly Miller Moss Out! line of moss controls offers several iron-based products to kill lawn moss quickly and benefit your lawn:

  • Liquid Lilly Miller Moss Out! 5 in 1 Broadleaf Weed & Moss Killer, available in a ready-to-spray and concentrate formula, kills lawn moss along with dandelions and other common broadleaf weeds. It even helps suppress fungal lawn diseases, including rust and snow mold. Treated as directed, mosses and weeds start turning black and dying within hours. The formula is rainfast within three hours as well.
  • Lilly Miller Moss Out! For Lawns, available in liquid ready-to-spray and economical concentrate formulas, targets lawn moss with liquid iron for superior results. Used as directed, this product delivers results in hours and kills moss quickly and thoroughly.
  • Granular Lilly Miller Moss Out! For Lawns, available in two convenient sizes to suit small or large lawns, contains 10 percent iron. An essential plant nutrient, iron kills mosses and promotes rich, green color in your lawn – without stimulating growth that translates to more mowing. When applied according to label instructions and watered in to release the moss-killing action, these granules yield visible results in hours.
  • Lilly Miller Moss Out! For Lawns Plus Fertilizer 20-0-5 granules combine 10 percent iron with a nitrogen-rich, 20-0-5 lawn fertilizer to kill existing moss quickly and feed your lawn. Used as directed, you'll see results with moss in hours. Plus, the extra plant nutrients promote thick grass and help combat moss growth. 

Always follow product label instructions closely, and only use these products on lawns. Iron-based moss controls naturally cause rustlike stains, which can affect sidewalks and other hard surfaces.

Effective iron-based products kill moss and improve your lawn at same time.

Preventing Future Lawn Moss

To keep your lawn free from moss, take steps to correct the problems that allowed moss to grow. A soil test will confirm if your lawn needs lime to reduce soil acidity and encourage healthy grass growth. Take time to improve areas with poor drainage, and consider thinning nearby trees or shrubs to let more light reach grass below. If your soil is compacted, aeration helps reduce opportunities for moss to take hold – and regular lawn maintenance goes a long way toward keeping grass healthy and strong.

By improving your lawn's conditions and treating moss with effective products, you can kill moss quickly and keep it gone. Lilly Miller Moss Out! products can help you put unsightly lawn moss behind you and reclaim your turf for thick, green grass instead.

Lilly Miller and Moss Out! are trademarks of Central Garden & Pet Company.

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