Does Roundup Kill Moss

Have you ever seen extensive areas of moss on your lawn when you peek out the window? While moss is not technically a weed, it acts in the same way and can affect the health of your lawn.

Moss is a primary plant with a shallow root system, and as an opportunistic plant, it can quickly take over any available space. Moss grows wherever in your yard; your grass isn’t thick enough to crowd it out.

Fortunately, dealing with moss on your lawn isn’t too much of a challenge. However, to make the task easy, many new gardeners often ask, does weed killer kill moss, particularly Roundup moss treatments?

In our guide, you can learn more about moss weed and the best ways to deal with it. By the end, you’ll have enough information on, is roundup safe to use on your lawn and around other plants, and also the potential of tackling roof moss using the same techniques. (Read Round Up For Lawns)

Guide and Tips To Kill Moss

What Is The Best Way To Kill Moss?

Moss is a primary, shallow-rooted plant. It can operate as a groundcover in your lawn, filling up gaps where your grass is sparse. However, moss removal is only the first step toward overall moss control.

Chemical Method

To get rid of moss in your lawn, you must first destroy the living plant. You may find moss herbicides in your local garden store.

Many products contain iron and can feed your lawn while killing moss. Find a moss-specific product. Others may work on moss but may damage your turf.

Herbicides work best when applied during moss’s active growing season. Moss grows best in moist, chilly conditions, usually in spring or early October. Of course, if you miss the perfect season, you can still apply herbicide. Herbicides can kill moss any time of year.

Organic Method

If you don’t want to use herbicides on your moss gardens or want something simple to use, you have simple moss-killing methods. You can kill moss by mixing mild dish soap or baking soda with lukewarm water.

  1. Use 2-4 ounces of soap per two gallons of water.
  2. Pour 2 liters of water with a small box of baking soda
  3. Two gallons should cover 1000 sq ft of mossy grass.
  4. Increase the solution concentration while keeping the same ratio.
  5. Apply a thick application of the solution with a garden sprayer. For maximum effect, soak the moss using a garden sprayer. Using this method luckily doesn’t harm your lawn. The moss should die and turn orange or brown in 24 hours.
  6. After the moss dies, use a metal rake to remove it. Collect the dead moss and keep it in sealed bags away from your grass.

Stop Moss Growing Back

To get rid of moss in your lawn and prevent it from returning, you must address the conditions that allowed it to flourish. While soil conditions may not always promote or prevent moss growth, they can indicate some soil issues. (Find the Best Grass Killer For Flower Beds)

Manage Soil pH get rid of moss

Manage Soil pH

Moss thrives on acidic or low pH soil. Conduct a soil test to determine the level of your garden’s pH. The most common solution for acidic soil is lime.

Adding lime in the fall allows winter rain and snow to break it up and help it seep into the soil. However, it can take months for lime to reduce soil acidity for killing moss. Fast-acting lime can be used if you need faster action.

Is Your Lawn Draining?

A mossy grass may suggest poor drainage. Moss thrives in damp areas. Also, if poor drainage prevents good turf growth, moss can form in thin patches of turf. To get rid of moss in your lawn, fix drainage problems.

Poor drainage has many causes. First, the soil type may not drain well. Clayey soils drain slower than sandier soils. Aerating clayey soil and adding humus or compost can help improve it.

Poor drainage is also caused by compacted soil from heavy traffic. The soil is probably compacted if your lawn gets a lot of foot traffic, whether from kids or other activities.


Moss is a shade-loving plant, whereas most turfgrass is sun-loving. Every day, even shade-tolerant turfgrass requires 6 hours of direct sunlight or 12 hours of partial sunlight. If your grass is struggling to thrive and moss is taking over, try lowering the shade.

Will Roundup Kill Moss and Algae?

The wet soil beneath the trees may not grow grass but can be green with mosses. However, you may have a few weeds in certain areas, and you think about getting rid of both using Roundup.

While glyphosate-based products like Roundup kill weeds and grass, they do not kill moss. Thus, if you want a quick solution for roof moss, then you need another solution.

Leaf and sap in weeds absorb glyphosate, the active element in Roundup. Once in the sap, it travels through the plant’s vascular system, killing the leaves, flowers, and roots in a few hours.

After the Round-Up has dried completely, you can go back to work in the garden. Weeds should wilt and die within hours.

Round-Up is used for controlling weeds, where glyphosate is a nonselective pesticide that kills weeds growing and is tightly bound to garden plants alike. But it won’t work on a moss garden or algae.

It isn’t only the Roundup nonselective herbicide that cannot eliminate moss. You can discover the failure of many common herbicides, as seen in Christmas tree plantations or other perennial crops treated area where competing higher plants are killed by herbicides, leaving a green carpet of mosses and other bryophytes thriving.

The reason glyphosate does or doesn’t kill mosses remain unclear. Stronger glyphosate formulations combined with herbicides, such as triclopyr, kill woody vines and shrubs.

In addition, Roundup can kill grass, and desirable garden plants, so you need to use it with some caution for weed control.

Ferrous sulfate and Copper sulfate

  • Iron retards mosses but has minimal effect on growing grass. But iron does not permanently destroy moss. It may “burn” the moss and weaken the plant.
  • To get rid of moss, it must be removed and replaced with thick turf grass seed.
  • Moss can be controlled using Iron Sulfate and Ferrous Ammonium Sulfate at a level of 3 oz. Iron Sulfate in 5 gallons of water.
  • Spray the five-gallon mixture over a 1000 sq. ft. area.
  • You can also use copper sulfate, 2 to 5 ounces per gallon of water, to do the same thing and control moss where 4 gallons of spray cover 1000 sq ft.
  • However, it may stain hands and clothing and corrode metal items. Copper sulfate spray can also harm aquatic habitats and should be avoided.

Kill Lawn Moss and Keep It Away

Controlling moss in your lawn may seem difficult once it has established itself, but it is easier than you think. It involves dealing with existing lawn moss and fixing factors that encourage its growth.

Follow these steps to get rid of lawn moss and enjoy lush green grass:

To effectively control moss, first recognize that it isn’t like other grass “weeds.” Plants do not process water and nutrients like sophisticated plants. So weed killers won’t kill mosses. Even potent pesticides designed to kill all plants cannot kill or prevent moss.

Though mosses appear to push lawn grasses out, the truth is far more straightforward—the acidic, extremely damp, or compacted soils that grasses hate.

Mosses thrive in similar environments. Moss reproduces where grasses fail, and you’ll discover moss isn’t common on lawns that have vigorous grass growth.

Control Existing Lawn Moss

When moss is actively growing, treat it. This usually occurs during the autumn, winter, and early spring rains.

Lawn mosses need little light or food to survive, but they need external and internal moisture.

Iron-based moss management chemicals, such as ferrous sulfate, kill lawn moss by drawing away moisture, causing it to dry out, become black, and die, unlike Round Up spray, many need to be used with caution near hard surfaces.

To help your grass, the Lilly Miller line of moss killer treatments includes many iron-based products:

MossOut to eliminates lawn moss

5 in 1:

Broadleaf Weed & Moss Killer eliminates lawn moss, dandelions, and other broadleaf weeds at the same time. It helps control rust and snow mold on lawns. When treated as prescribed, your moss problem and weeds die within hours. The algae killer formula is also rain-fast in three hours.


For lawns, the best moss killer attacks existing moss with liquid iron for more significant results. When used as suggested, this product spray destroys moss and moss spores in hours.


For lawns and killing moss, you have two convenient packages, including 10% iron. Iron, a vital plant nutrient, eliminates mosses and promotes lush green lawns without encouraging excessive growth and mowing.

Moss Out and Fertilizer:

These granules blend 10% iron with a nitrogen-rich 20-0-5 lawn fertilizer to kill moss quickly and fix low soil fertility, thus increasing better growing conditions for your lawn in your yard. When used as instructed, moss results in hours. The increased plant nutrients help thicken the grass to fight both weeds and moss.

Always read product labels and only use them on lawns. Iron-based moss treatments naturally generate rust-like stains on hard surfaces like sidewalks.

Prevent Future Lawn Moss

Take efforts to fix the faults that allowed moss to grow in your lawn to maintain it clear of moss. If your lawn requires lime to lower soil acidity and promote healthy grass growth, a soil test will confirm this. (Find the Best Grub Killer)

Consider cutting neighboring trees or shrubs to allow more light to reach the grass below and improving areas with poor drainage. Aeration helps lessen the chances of moss taking hold if your soil is compacted, and regular lawn upkeep goes a long way toward keeping grass healthy.

Does Roundup Kill Moss

Leave a Comment

Your email address will not be published. Required fields are marked *