How to Remove Moss on Concrete [Natural and Chemical Methods]

Moss, though ecologically significant, can be an enemy to the aesthetics of concrete surfaces. Whether it is growing on your patio or sidewalk, it is hardly possible to remain unperturbed by the site of unattractive moss.

Do you want your walkways and pavers to look awesome all year long? We’ll share with you some priceless tips and tricks on how to remove moss on concrete and keep it gone.

Read on!

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Why does moss grow on my driveway on concrete

A driveway accentuates the dramatic detail of your entire home. However, the general appearance of the concrete on your driveway may deteriorate, especially in some seasons. The most common reason for this deterioration is moss growth. You might then wonder why moss grows on your driveway on concrete.

Here’s why. Moss tends to have a knack for damp concrete surfaces like your driveway or patio. Overhanging trees and plants that cast shadows over a moist concrete surface create ideal conditions for the thriving of moss. 

Surprisingly, moss will attain maturity within six weeks, contrary to other species that can take two years or more. If you have noticed moss growths on your driveway, you might want to check out some factors that precipitate/promote moss growth like; 

• Shade

Unlike many other plants, sunlight discourages moss growth. You should check for the presence of plants, whether trees, shrubs, or overhanging branches, that seem to overshadow your concrete surface.

Whether partially or fully shaded, such surfaces will promote moss growth. It would be best if you considered cutting or trimming the plants to allow concrete exposure to sunlight. Also, cutting back overshadowing plants opens up the area to wind. This improves circulation, which helps in drying damp or moist surfaces.

• Soil

Soil on the surface of your concrete is a common find, especially on driveways. Whether introduced by your car or runoff water, the soil will often find its way to your driveway. That being the case, this soil promotes the growth of moss.

Worse still, moss can flourish in basic and acidic soils. Moist/damp conditions favor moss growth. Soil can maintain dampness for long periods, aggravating the moss issue further. 

If you see soil on your driveway’s external concrete surface, try to sweep it away. You will not only prevent moss growth but also make cleaning and maintenance routines much easier.

• Moisture

Water is one of the most notorious culprits that aggrandize moss growth. Moss blooms in damp/moist conditions, and concrete tends to be a perfect spot. Inappropriate drainage on your driveway might be the reason you’re repeatedly dealing with the moss problem.

While it is insignificant to try and shield your entire driveway from rain, you ought to ensure that water does not overflow. You can also open up the space for exposure to wind and sunlight. This encourages faster water evaporation hence keeping your driveway dry.

• Cracks

If your concrete driveway has some evident cracks, you might want to repair them. This is because moss spores from close plantations tend to be blown into the cracks. You will then notice a dense cover of moss on your driveway. 

How to remove moss on concrete 

Moss tends to have an unusual liking for concrete surfaces, a phenomenon that does not sit well with many homeowners. It is a green plant that grows with a dense clumpy, or mat-like appearance on your driveway or other outdoor areas with concrete surfaces. 

You will likely see moss, especially during cold seasons or if you live in warm and humid regions. Dampness and shade are major precipitating factors for the growth of moss. It is not particularly hazardous to humans but still undesirable in most households. 

You’ll agree that surfaces invaded by moss are pretty unsightly. What’s more, moss can also ruin concrete. After setting in, it retains moisture that then damages the underneath surfaces. 

On that account, you’ll be doing yourself a favor by learning how to remove moss on concrete.

Thankfully, clearing moss is easy and achievable using multiple remedies like baking soda, boiling water, bleach, pressure washer, and vinegar. 

But first, how about we look at some of the basic necessities that can be useful in moss removal? Note that the tools depend on the method you choose for clearing moss. They include;

• Rubber gloves

Some moss removal methods involve using harsh chemicals that may be harmful to your skin. It is, therefore, a brilliant safety measure to wear protective gear like rubber gloves to avoid damaging your skin.

• Stiff/scrub/wire brush

Contrary to most plants with roots, moss uses rhizoids to attach to concrete. For some moss removal methods, you will need to scrape away the moss with a powerful tool. A stiff brush will do a great job of clearing moss, even from cracks and between pavers.

• Push broom

Once you’ve scraped off the moss growth, you will need to clear the debris from the surface. A push broom enables you to sweep the moss debris and other remnants for easy collection.

• Spray bottle

A spray bottle is essential for most methods that use solvents or chemicals. It would be best if you prepared the solutions in the spray bottle as you can shake and mix the components. Also, spraying is an ideal method of applying the preparation over the mossy area.

• Garden hose

You will sometimes have to hose down the concrete surface after clearing the moss growth, especially by hand. You can incorporate a sprayer attachment on your hose for increased efficacy.

The tools mentioned above will, at times, suffice in eradicating moss. For instance, if you’re dealing with small patches of moss, an intensive cleaning routine with some of these tools will do. However, this is not always the case. 

To enable you to get the right gist of it, below is an in-depth guide that encompasses the different methods you can use for moss removal. The methods are provided under chemical and natural techniques and include;

How to Remove Moss on Concrete: Natural Methods 

• A mixture of vinegar and water

Using a vinegar is one of the most economical method to clearing moss from your concrete floors. White vinegar’s acidic nature (contains acetic acid) enables it to kill moss like clockwork. Even better, it also hinders the moss from growing back.

All you need to do is to prepare the vinegar solution by mixing one part water and the other part vinegar in a garden sprayer or spray bottle. Shake the ingredients well to mix. Spraying will be an ideal application method when dealing with extensive surfaces. 

You can spray your preparation onto the moss and allow it to sit for some days. Examine the surface to determine whether the moss is dead. It will appear brown once dry and dead. Use a scrub brush to eliminate the moss and then rake it up from the surface.

Alternatively, you can pour concentrated vinegar directly onto the moss. You will then let the vinegar sit for about ten minutes. Scrape the moss off using a stiff brush and clean the surface using a pressure washer. You might need to reapply the vinegar to spots with stubborn moss.

• Boiling water

If you are looking for a straightforward way of removing moss, boiling water is your best bet. You only need a pot/pan and a stove to get boiling water. It is quite an ideal option, particularly when you have plants near mossy areas. 

This method is gentle and environmentally friendly since it is devoid of chemicals that would likely damage other plants. Note that you may have to conduct this method repeatedly when dealing with tougher moss. 

Start by preparing boiling water. Once ready, pour the water over the mossy area carefully to avoid burning yourself. You can then use a stiff brush to scrub the area and hose down the surface to wash the debris away.

• Baking soda/ agricultural lime

Baking soda is one of the most c household reagents that befits the all-purpose description. You are in luck if you have it cached in your kitchen stash. Baking soda is a natural and economical way to the large moss patches on your sidewalk.

With a naturally alkaline nature (pH 8), baking soda creates a hostile environment that antagonizes moss growth. Its alkaline properties neutralize the acidic environment in which the moss blooms in.

The good thing is that it is easy to apply. You will just need to sprinkle the powder over the concrete surface invaded by moss. You will then let the powder or agricultural lime sit for 24 hours. Use a stiff brush to scrape the moss and other remnants and sweep them off. You can opt to clean the surface using a cleaning solution and water.

• Pressure/power washer

At times, you might want to avoid chemical methods of moss removal and opt for pressure washing. This method can remove moss from a concrete surface and clean it up as well. Simply equip yourself with plastic sheeting, a power washer, and protective glasses. 

Remember to cover items and plants near the affected area to shield them from the massive water pressure. Direct the nozzle about 2-3 feet away from the mossy area and then employ a side-to-side sweeping movement across the area. Ensure that you use a 250 nozzle tip.

How To Remove Moss from Concrete: Chemical Methods 

• Using household bleach

You can count on bleach solution to clear the moss, remove stubborn stains and even kill mildew. All you need to do is prepare a water and bleach mixture. However, before getting into it, you should exercise caution when handling bleach products, including ordinary household bleach.

This is because bleach can be toxic to your skin. Therefore, remember to wear some rubber gloves for protection. Also, something worth noting is that bleach is not a selective killer. This means that it will not only deal with moss but also damage any plants or grass if you accidentally apply it.

To prepare the mixture, mix one-part bleach and diluted one-part water in a spray bottle. Spray this solution over affected mossy areas and then allow the bleach mixture to soak into the moss for a few minutes. Scrape the moss debris off with a scrub brush and then hose down the surface. It is recommendable to seek garden bleach since it kills moss without damaging the environment.

• Ammonium Sulfamate

You have probably heard about the efficacy of this chemical as a weed killer (known as a broad-spectrum herbicide). You can turn to ammonium sulfamate to help clear the moss off your sidewalk. It comes as a white crystalline solid soluble in water and is primarily effective in controlling woody plants as a foliar spray.

Note that this is a dangerous chemical that contains many toxic qualities. You should therefore don some protective gear when using the chemical. Apply it to the mossy area using a watering can or a sprayer.

Caution is essential when applying to avoid grassy areas or other plantations that you don’t want to be damaged. After application (chemical treatment), wash down the debris clumps using a power sprayer. It would help if you remembered to adhere to the application guidelines provided in the product.

• Commercial moss killers

You might have to resort to powerful chemical agents if you are dealing with extensive and more established moss growths. A commercial moss killer will turn out to be valid. Besides being highly effective, moss killers are also bleach-free, meaning they will not stain your concrete pavers. 

How to prevent moss from growing on concrete

Moss can be a menace for many concrete surfaces. Luckily, you can keep your concrete floors clear of moss growth by treating them using chemicals, lowering moisture levels, improving drainage, opening up the area, and keeping soil away.

Moss has a tendency to grow where it shouldn’t, like on hard surfaces. Once it moves into your favorite outdoor entertainment area, it makes the spot an incredible eyesore. 

Here comes a more detestable part. The battle against moss growth on your driveway or patio can become bothersome and enervating. Don’t sweat it! Elaborated further below are solid techniques you can use to prevent moss from growing on concrete. They include;

• Chemical treatment

If you’ve just cleared moss from a concrete surface, you can keep it from regrowing by using moss control products. Most of these products work by killing and inhibiting the growth of moss, algae, and mold on outdoor concrete. 

Fortunately, these protective treatments are effective and non-corrosive, have clear drying, and bear low VOCs and minimal odor. By treating outdoor concrete surfaces, you turn them into non-slip surfaces, minimizing risks. It would be best if you treated concrete each spring or fall to prevent moss from growing.

• Lowering moisture levels

As earlier pointed out, moss flourishes on moist areas of concrete. Therefore, a brilliant way to prevent moss from growing would be to limit water to your concrete. You can achieve this by;

• Sealing concrete 

The substrate quality of concrete and the base layer on which concrete is laid promote the setting in of moss and subsequent growth. You’d be wise to seal your concrete, especially outdoors, to keep the moisture out. This way, your concrete will not be holding large amounts of moisture. 

Ensure that you use sealers with anti-slip properties to avoid making the surface slippery when wet. For this, utilize a penetrating sealer or combine it with an anti-slip additive. Also, remember to re-seal the concrete every two to five years.

• Keeping water sources away

Having sprinklers and taps close to the concrete surface predisposes it to overflow or becoming damp. This would create ideal conditions for moss to thrive. You ought to ensure that the water sources do not cause overflowing over the concrete surface or at least reach it.

• Opening up the area

For concrete areas prone to moss invasion, you can try exposing them to sunlight. Cut tree branches and trim shrubs that are hanging over the area. This way, you will continuously expose the surface to sun rays which prevent moss growth. 

Opening up the area by trimming the nearby greenery also encourages wind penetration. This means a drier concrete surface because of faster evaporation of moisture. In combination with increased sunlight penetration, you will have made a significant step towards winning the war of preventing moss growth.

• Improving drainage

If you notice water pooling on your concrete pavers or driveway after a heavy downpour, moss growth could be a looming problem. Water that sits on a concrete surface for prolonged periods tends to seep through concrete and reaches underneath. Besides, outdoor unsealed concrete tends to hold a lot of water. 

It would be best if you, therefore, avoided water pooling. It is recommendable to install concrete with a gradient. This way, the surface will have an unnoticeable slope (at least 0.5%) that enables water runoff. 

Another reliable hack for optimizing drainage is by establishing an additional drain. You might have to incur some extra costs when implementing this trick. However, it is rewarding, especially if your drainage is deficient or if you keep dealing with a flooding problem.

You should seek a drainage solution that drains water into a sunny area for faster water evaporation. The drainage should also avoid emptying water into spots where moss is growing.

Improving drainage also helps keep soil away. Often, the soil will find its way onto concrete surfaces, especially after a downpour or due to flooding. Soil settling on a concrete surface is a good breeding ground for moss. 

Best moss killer for concrete 

If the moss growth on your concrete pavers proves challenging to eliminate, a special type of vinegar will suffice. The Calyptus 45% pure super concentrated vinegar works like a charm in ridding moss from concrete.

To prepare this efficacious solution, combine 20 percent water with 80 percent vinegar. Pour this solution on the concrete areas affected by moss. If necessary, you can scrub the surface with a stiff or wire brush.

You will then allow the vinegar to sit for about 20 minutes or until you notice the color change of the moss from greyish green to yellow. Apply warm water to wash down the surface, and you’re good to go!

The vinegar solution is your best bet in tackling moss growth for a number of reasons. It is an excellent moss killer, pocket friendly, and easy to apply. You don’t have to dig deep into your pocket to clear moss off your concrete.

Alternatively, you can use white vinegar to get rid of moss. Prepare the solution by combining a part of vinegar and a part of water in a garden sprayer or bottle. Shake to mix and apply the solution by spraying.

The only difference is that with white vinegar, you will allow it to sit for a few days, after which you’ll confirm whether the moss is dead and dry. If otherwise, you can reapply the solution. Including salt in the solution increases the efficacy of this remedy. Interestingly, you can apply this mixture also to eliminate weeds.

The only catch when using Calyptus 45% is that you must restrict your pet(s) from accessing the vinegar-treated surface before thoroughly rinsing it. This is to avoid vinegar consumption (licking), as it can be hazardous to pets.

The video below illustrates how to remove moss on drives and patios at your home. Read and learn about the natural and chemical methods.

How To Remove Moss from Concrete : Frequently Asked Questions- FAQs 

Q1. Does moss damage concrete?

Besides making your concrete sidewalk or pavers look untidy, does moss really harm concrete? Yes, it does. Once it sets in and takes root on concrete, it tends to retain moisture which is a vital requisite for its growth. 

When neglected for long periods, this moisture degrades the underneath surface. Once it flourishes, it will anchor abundantly on the concrete surface and become quite messy to deal with. Also, note that it makes the concrete surface a potential hazard as it can cause slip accidents. 

Q2. Will a pressure washer remove moss from concrete?

Yes, it will. In fact, it is one of the quickest ways of clearing moss from concrete. All you need to do is spray high-water pressure at the mossy area and blast the moss away from the concrete. 

You can also aim the nozzle at the affected area and employ a side-to-side motion. The intense pressure of water removes the moss effectively. Note that, at times, high-pressure cleaning depends on how much moss you’re dealing with. Power washing is particularly effective on fuller or thicker moss growth. 

Q3. Does moss killer stain concrete?

Similar to fertilizers, moss killers are capable of staining concrete. Products like Lilly Miller Moss out for Lawns Concentrate will impact a stain on concrete, especially if it was over-sprayed. 

It is advisable to hose down the concrete area treated with the moss killer right after spraying to prevent staining. If the concrete is already stained, you can seek some commercial agents like Super Iron Out that are particularly made to eliminate such stains.  

Q4. What is the chemical that kills moss?

Ferrous sulfate, a sulfate of iron, is the ideal chemical that faithfully deals with moss. You have probably heard of this traditional product that is commonly sold as a fertilizer. It contains FeSO4, which is the active moss-killing component of most moss killers.

Opting for ferrous sulfate-based moss killers is one sure way of killing moss. Spray it over the affected area a week or two before clearing the moss. It makes the moss partially desiccated, enabling easier raking.

Q5. Does salt kill moss on concrete?

Surprisingly, salt can kill most moss species except the Schistidium maritimum, which grows in the salty coastal sea air. While moss thrives in shady and damp conditions, it also flourishes in acidic or compacted soils.

Alkaline environments/soils have high salt levels. This makes moss intolerant to alkaline soils. For this reason, salt will kill moss by creating an alkaline environment. Before applying a sodium-laden treatment to clear moss, remember to pre-treat the mossy area of interest.

Conclusion

Moss is one of the most nefarious guests that show up uninvitedly in many homes. What’s more, moss will transform your favorite outdoor chill spot into an irritating site once it sets in. However, you don’t have to sit back as moss flaws the appearance of your concrete surfaces.

Here’s a valuable tip. It would be best if you opted for various natural and chemical-free solutions like vinegar and baking soda to kill and keep moss off your concrete. Note the highlighted chemical methods are also effective, especially with stubborn mosses. 

In closing, this article exhaustively gives insight into how to remove moss on concrete to help you reclaim your outdoor space. You can choose any of the multiple remedies to help you resolve your moss problem once and for all!