How to Remove and Prevent Moss in Lawns

Moss is a common problem in many lawns, especially in shady, damp areas. While some people may find moss aesthetically pleasing, it can cause problems for your grass. Moss competes with grass for space, light, and nutrients. If left unchecked, moss can take over sections of your lawn or your entire yard. The good news is that removing and preventing moss is usually straightforward with some DIY lawn care. This article provides a comprehensive guide on how to get rid of and stop moss from returning to your lawn.

What Causes Moss in Lawns?

Before learning how to remove and prevent moss, it helps to understand what causes moss to grow in the first place. Here are some of the most common reasons moss can take hold in your yard:

Shade – Moss thrives in shady areas where grass struggles to grow. Too much shade from trees, shrubs, fences, or buildings can create an environment ideal for moss.

Excess moisture – Frequent watering, poor drainage, compacted soil, and other wet conditions promote moss growth. Moss prefers dampness, while most grasses do best with good drainage.

Low soil fertility – Soils lacking in key nutrients like nitrogen, phosphorus, and potassium can lead to poor grass growth and allow moss to move in.

Low soil pH – Acidic soils below pH 6.0-6.5 favor moss over grass. Liming to raise pH can help discourage moss.

Compaction – Dense, compacted soils prevent water and nutrients from reaching grass roots properly. Aerating alleviates compaction.

Thatch buildup – An excessive thatch layer of dead grass blades and stems provides an ideal seedbed for moss. Dethatching removes this favorable environment.

By understanding what environmental conditions moss thrives under, you can make adjustments to your lawn care practices to create less hospitable conditions for moss and better growing conditions for grass.

Removing Existing Moss from Your Lawn

If you already have moss established in your lawn, the first step is removing the current growth. Moss has a relatively shallow root system compared to grass. This makes physically removing moss growth an effective first step before applying other moss prevention measures. Here are a few handy methods for taking out existing moss:

Manual Removal

Manually raking, pulling, or scrubbing moss out by hand is labor-intensive but often highly effective for spot treating small areas.

Steps for manual moss removal:

  • Use a stiff rake, push broom, or scrub brush to aggressively loosen the mossy layer from the soil beneath.
  • Grab clumps of moss and pull up as much of the growth as possible by the roots.
  • Rake vigorously again to remove any remaining moss debris or loosen any attached moss.
  • Remove all moss debris from the lawn to prevent re-growth from any remnants.
  • Allow the area to dry out completely before reseeding with grass.

Repeat this manual process weekly as needed until moss is under control.

Power Dethatching

For larger lawns, renting or purchasing a mechanical power dethatcher can make removing moss much less labor-intensive. Power dethatchers use stiff tines or blades to rake up and lift matted layers of moss and thatch from lawns.

Tips for power dethatching moss:

  • Use a verticutter dethatcher for the best moss removal. Verticutters have vertically rotating tines that rip moss up by the roots.
  • Make several passes in different directions to ensure complete moss removal.
  • Adjust the dethatcher tines lower to dig into the mossy mat. But avoid going so low as to damage the soil surface excessively.
  • Dethatch when the lawn is damp but not soggy for better moss extraction.
  • Remove and dispose of the moss debris after dethatching so it doesn’t re-establish in bare areas.

Chemical Moss Killer Application

Using chemical moss killers containing ferrous (iron) sulfate or other active ingredients can help remove established moss and keep it from returning.

How to apply moss killer products:

  • Mow the lawn short and remove any moss debris before application.
  • When applying liquid formulations, use a tank sprayer for full lawn coverage. Granular products can be spread with a broadcast spreader.
  • Follow product label rates carefully to avoid lawn injury. Do not over apply.
  • Make two applications 2-3 weeks apart for best moss eradication.
  • Allow 3-4 weeks after the last application for the moss to blacken and die. Then rake vigorously to remove dead moss.
  • Overseed any bare spots after moss removal to establish new grass before moss reappears.

Liming if Soil pH is Low

One of the underlying causes of moss problems is low soil pH. If your lawn has a pH below 6.0, applying lime can help raise the pH closer to the ideal range of 6.5-7.0 for grass. This less acidic environment makes it much harder for moss to thrive.

How to lime your lawn:

  • Do a soil test to determine exactly how much lime is required to reach the target pH.
  • Choose fast-acting calcitic lime unless soil test states dolomitic lime is needed.
  • Apply lime anytime the lawn is actively growing, usually early fall or spring.
  • Use a drop spreader for even particle distribution, applying half the amount in perpendicular passes.
  • Water lightly after liming to move particles into the soil profile.
  • Allow 4-6 months for full pH change. Retest soil pH again before applying more lime.

Liming is most effective when combined with the other moss removal and prevention methods in an integrated lawn moss control plan.

Preventing Moss From Returning

Once you’ve successfully removed existing moss, it’s crucial to take proactive steps to prevent moss from reappearing again later. Here are some of the best ways to stop moss from gaining another foothold in your lawn:

Improve Light and Air Circulation

Since moss thrives in dark, damp environments, increasing light exposure and air movement provides less favorable conditions.

Ways to open up shady lawns:

  • Strategically prune back overhead tree branches to let in more sunlight.
  • Limbs up low hanging branches for better air circulation near the ground.
  • Thin out dense shrubbery around the lawn’s perimeter.
  • Remove landscape features like boulders that can block light and airflow.
  • Moss often first appears in the most shaded areas. Focus efforts there.

Letting in more light and allowing air to move freely through the lawn makes the environment less hospitable for moss. But take care not to over-prune trees and shrubs. Leaving some shade is still important for grass health during hot, dry periods.

Maintain Proper Soil Moisture

Since moss loves a persistently damp lawn, modifying your watering and drainage practices can make a big difference in preventing moss from returning.

Tips for improving soil moisture:

  • Water thoroughly but infrequently, only as needed based on grass requirements.
  • Allow the soil to partially dry out between waterings.
  • Early morning is the best time to water if needed. Avoid late day watering.
  • Adjust sprinklers to avoid excessive overlap and runoff.
  • Improve drainage of low, chronically wet spots with aerating, topdressing, or grading.
  • Direct downspouts and gutters away from the lawn.
  • Reduce shade and compaction that restrict evaporation and drainage.
  • Consider installing subsurface drain lines in problem areas that remain soggy.

Keeping soil consistently wet feeds moss growth. By improving drainage and moisture control, it’s harder for moss to thrive.

Maintain Proper Lawn pH

As mentioned earlier, moss prefers acidic soils. Regularly liming your lawn as needed based on soil pH test results helps keep pH in the ideal slightly acidic range for grass.

pH management tips:

  • Test pH yearly and lime if below 6.0. Target 6.5-7.0.
  • Use dolomitic lime if soil test recommends it. Otherwise, calcitic lime works.
  • Apply lime at least 2-3 months before or after moss killer use.
  • Adjust irrigation water pH if it is highly acidic.
  • Certain fertilizers can lower pH over time. Monitor pH regularly.

Keeping pH from becoming too acidic denies moss an environment that favors its growth over grass. Routine soil testing and pH adjustment is key.

Improve Soil Fertility

Rich, fertile soil grows thick, vigorous grass that resists moss encroachment. Moss takes advantage when grass is thin and weak. Wise fertilization provides nutrients lawns need without overdoing it.

Fertilizing suggestions for moss prevention:

  • Perform a soil test to determine specific nutrient needs.
  • Use a complete fertilizer that includes nitrogen, phosphorus, and potassium tailored to soil test recommendations.
  • Organic fertilizers work well if applied at proper rates.
  • Focus fertilizer applications in the growing season during periods of grass recovery.
  • Avoid heavy use of high nitrogen quick-release synthetic fertilizers that can push top growth at the expense of roots.
  • If soil test phosphorus levels are adequate, use low or no phosphorus fertilizer.
  • Alternate fertilizing with deep root feeding.

Robust grass growth from proper fertility minimizes opportunities for moss to invade bare or thinning areas. Give your lawn what it needs, but don’t overdo it.

Reduce Soil Compaction

Compacted soils are favourable to moss because water and nutrients cannot penetrate down to the grass roots properly. Aerating alleviates the dense layers that moss tends to thrive on.

Aerating tips:

  • Use a core aerator that removes plugs of soil to create air and water channels.
  • Aerate at least once per year, preferably in early fall.
  • Make multiple passes in crossed directions for thorough aeration.
  • Improve aeration results by topdressing with compost after aeration.
  • Consider frequent, light aeration of high traffic or wet areas.
  • Reduce unnecessary foot traffic over the lawn.

Better soil structure removes the firm surface moss loves to establish in. Don’t forget to aerate!

Dethatch if Thatch Buildup is Severe

Some thatch buildup in a lawn is normal and beneficial. But excessive thatch layers create optimal conditions for moss growth. Regular dethatching removes this favorable seedbed.

How to manage thatch:

  • Use a dethatching rake or power rake to reduce excess thatch depth to under 0.5 inch.
  • Dethatch in early fall when lawns are actively growing and can recover faster.
  • Remove and dispose of thatch debris after dethatching to prevent recolonization.
  • Overseed any thin or bare areas after dethatching.
  • Adjust mowing heights up slightly to encourage deeper grass roots that decompose thatch faster.
  • Apply acidifying nitrogen fertilizers to help decompose thatch layers.

Controlling thatch accumulation ensures moss cannot exploit excessive buildup. But avoid overdoing dethatching, which causes considerable lawn stress.

Timely Moss Killer Application

Even with preventative measures, moss spores in the environment can slowly re-establish in lawns over time. Spot treating small areas of new moss growth with moss killers containing iron, zinc, or other active ingredients can stop it before it gets out of hand again.

Tips for timely moss killer use:

  • Scout for early light-green moss growth in spring or fall and treat promptly.
  • Spot spray liquid moss killer formulations using a tank sprayer.
  • Use granular products carefully only where new moss is noted.
  • Follow label application rates exactly. Do not over apply.
  • Allow grass to dry before and after application to avoid turf injury.
  • Make follow up applications 2-3 weeks later if moss persists.

Catching and treating moss outbreaks early prevents recurrence of serious widespread infestation later. Be vigilant for new growth.

Frequently Asked Questions About Moss in Lawns

Here are answers to some common questions about removing moss and keeping it out of lawns long-term:

Does Moss Indicate My Soil is Unhealthy?

Not necessarily. Moss moving into lawns is often more indicative of certain environment conditions rather than poor soil quality. Moss likes things damp, shady, and acidic. Optimizing those environmental factors is usually more important than general soil enhancement for controlling moss.

Is Manual Moss Removal Effective?

Manual removal by raking, power brushing, and hand pulling can be highly effective at removing moss, especially if repeated diligently. Manual removal is often easiest for spot treating smaller areas. Allow grass to regrow and fill in the areas where moss was removed.

Will Reseeding With Grass Make Moss Go Away?

Reseeding alone does little to prevent moss from returning quickly. For new grass seedlings to establish successfully, the environmental conditions that enabled moss must be corrected first. otherwise moss will recolonize rapidly again depriving new grass of light and space. Integrate proper seeding with other moss prevention measures.

When is the Best Time to Dethatch My Lawn?

The optimal time for dethatching cool-season grasses is early fall when grass is actively growing. This gives it enough time to recover before winter dormancy. Avoid dethatching in spring just before summer heat stress. Never dethatch warm-season grasses in fall. For them, late spring is best.

How Often Should Lime Be Applied to Raise Soil pH?

Lime should only be applied based on soil test pH results, normally no more than once per year. It takes lime several months to fully react in soil, so avoid over application. Only apply enough lime at a time to reach the target pH. Retest soil pH before adding more.

Will Moss Killer Hurt My Grass?

When applied according to label rates and directions, quality moss killer products containing ferrous sulfate or other active ingredients selectively target moss and spare grass. Some temporary discoloration of grass may occur but it recovers quickly. Excessive rates can damage turf. Always read and follow product use guidelines.


Uncontrolled moss growth can become a major nuisance diminishing your lawn’s appearance and health. While small amounts of moss do not harm grass significantly, heavy infestation left unchecked often results in thinning turfgrass. By combining proven methods of mechanical removal, cultural practices, and chemical control, moss can be successfully eliminated and prevented from recurring in your lawn. Paying attention to proper lighting, soil moisture regulation, fertility, pH, aeration, and thatch management fosters conditions favorable for vigorous grass growth and unsuitable for moss. When integrated together diligently over time, these best practices provide effective, eco-friendly moss control and prevention for healthier, more attractive lawns long-term.