Moss can be highly damaging to any surface, including concrete. It also doesn’t take very long to spread, so you’ll want to deal with it as soon as possible. Letting it keep growing could ruin the cement and cost a lot to fix.
You can keep moss from growing on cement by treating the surface with moss control chemicals. You’ll also want to keep the concrete dry and away from the soil. Adding more direct sunlight by reducing shade also helps drastically.
So, if you see moss on your concrete, you’ll want to try these removal methods. I have included all the essential steps below, so let’s begin.
1. Use a Moss Control Treatment
One of the most effective moss removal methods is to use a special chemical treatment. Various treatments kill moss and make it difficult for it to return.
A good option would be the Wet & Forget Outdoor Moss Remover from Amazon.com. It comes with a convenient sprayer to make applying the treatment easier. It’s also bleach-free and works well on multiple surfaces, including cement.
Most moss control treatments work by drying out the moss. Since it needs water to live and reproduce, the moss dies quickly after the first application. Depending on your product, you may need to apply the treatment several times for the best results.
Some of the most effective chemical treatments use iron in their ingredients. However, you should avoid using iron-based products on cement. The iron causes the moss to darken and turn black, then die a few days after application. However, iron can stain cement surfaces, ruining them.
You must always ensure the moss control treatment is suitable for cement before buying it.
Is Moss Killer Harmful To Gardens?
Moss treatments can contain chemicals that also will kill your plants. If you’re worried about the treatment running off and getting into your garden, you can skip it. There are plenty of alternatives that don’t use any chemicals.
Chemical moss killers are best for when the moss has taken over a large expanse of cement, and you can’t deal with it efficiently on your own. You might not need it in every situation, but it’s an effective moss removal method, so it’s worth bringing up.
Should Moss Be Removed?
You should remove moss on your concrete, including driveways, sidewalks, and roofing. While it’s usually fine in soil, moss on these surfaces can cause much damage. It also makes walkways very slippery and unsafe to walk on.
Generally, you want to remove moss as soon as it starts growing on your concrete. It can become too hassle if it grows enough to cover the entire cement surface. Plus, many people find that it doesn’t look nice and makes areas appear abandoned.
You don’t always need to remove moss, however. It isn’t harmful to plants, so it can live safely in soil or grass. You may need to remove it if it starts taking over your property, but the moss won’t kill anything growing in your garden.
If the moss starts growing on your roof, you must remove it immediately. The moss can cause severe damage to your home and make it unsafe to live in quickly.
I’ve written another article discussing whether removing moss from your garden is advisable. Don’t miss it: Should You Remove Moss from Your Garden? 6 Facts
2. Keep the Concrete Dry
Moss loves moisture and can’t survive without it. Keeping the concrete dry can help kill moss and prevent it from returning. You’ll need to consider where the water’s coming from and why it’s pooling on your hard surfaces.
Sometimes, your yard needs to have more drainage. If your yard is full of compacted soil, it won’t absorb rain, leaving it pooling somewhere on your property.
You might also need to move garden sprinklers that spray over the concrete. Keeping the surface as dry as possible is sure to help.
Why Does Moss Love Moisture?
Moss cannot survive without water, and it relies more on moisture than most other plants to grow. The cells in the moss absorb water, which is where the plant gets most of its nutrients. Moss also uses water droplets to reproduce by spreading its reproductive cells.
So, you’ll only ever see moss somewhere that’s moist. By keeping your cement as dry as possible, you can eliminate it in no time. The moss won’t be able to get nutrition or spread further, making it much easier to deal with.
You might not need a chemical treatment if you can successfully keep your cement dry.
3. Remove Nearby Soil
Moss can also grow over the soil, although it generally prefers soil that’s not in good condition. If you notice dirt on your cement slabs, you’ll want to sweep it off as soon as possible.
Soil can hold in the moisture that the moss loves. Plus, it can quickly spread its thin roots through even the smallest layer of soil.
Moss growing in your garden or lawn can spread quickly to any concrete slab on your property. You’ll also want to treat these areas to prevent the moss from growing over your driveways, sidewalks, and other concrete paths.
Moss isn’t picky when choosing a place to grow. However, removing stray dirt when you see it can reduce the chances of moss overtaking your cement surfaces.
What Soil Conditions Does Moss Prefer?
While moss prefers acidic soil conditions, it’s very hardy and can grow in alkaline soil. You can see moss growing just about anywhere, even without soil.
Moss loves soil that doesn’t have good drainage. Adding some perlite to your garden can help make the soil healthier for your plants and less appealing to moss at the same time since it enhances drainage. Doing so can prevent moss in your soil from spreading to your cement, so it’s usually worth it.
For more information, check my article on using alternatives to rocks in a planter: 7 Alternatives to Using Rocks in a Planter
Overall, moss does have some soil preferences, but that doesn’t stop it from growing anywhere it wants to.
4. Increase Sunlight on the Cement
Next, you’ll want to do your best to increase the amount of sunlight that hits the cement. Shade encourages moss to grow, even on solid surfaces. However, it struggles to grow in areas with consistent sunlight because the warmth evaporates water that the moss needs.
You can trim back tree canopies and shrubbery without killing the plants, allowing more light to get through. Pruning trees can also be good for them since it encourages more growth.
If your home or another structure blocks light from reaching the cement, you can use a mirror to help direct sunlight. You could also paint the structure white since that color reflects more light, helping to brighten the area around the cement.
Moss needs moisture and shade to grow and spread. If you remove as many of those elements as possible, the moss will die off rapidly.
Can Moss Tolerate Sunlight?
Most moss species tolerate the sun, though they all prefer to live in the shade. Making your cement slabs brighter can reduce the moss that grows there. Moss needs a lot of moisture to survive, and the shade prevents evaporation from happening too fast.
Moss is an extremely hardy plant, so while it prefers shade, it can still survive in the sun after it’s established. You’ll want to give the moss more sunlight to help eliminate it. If the moss doesn’t go away, you should try to identify its species. It could be one of the few mosses that prefer to live in the sun.
In short, moss can tolerate the sun but usually wants to live in the shade instead. Most species of moss will like living in dark places more.
5. Rake the Moss
Moss also uses fragile, short roots to hold onto the surface of the cement. Sometimes, you won’t need to try any complicated treatment to get rid of it. Instead, you can simply use a rake to rip up the moss.
Once you have the moss, add it to your potted plants or shred it into mulch for your garden.
This method removes the moss, but you must do it several times to prevent it from returning. Not changing the conditions of the cement will leave it an excellent place for moss to grow, but moss is still very easy to rake up.
If you try raking it and you’re having issues, you can always try to dry out the moss first and get some more sunlight on it. As the moss becomes dry, it also gets brittle and weak, making it easier to rake up.
Try a Wire Brush Instead
If removing moss from a more minor cement patch, you can use a wire brush to get better results. These tools are strong and can easily reach between the cracks in the pavement. The most effective method would be to rake as much of the moss as possible, then go over all the crevices with a wire brush.
A great example of a wire brush for this project would be the Lavaxon Wire Brush from Amazon.com. This brush is thin enough to get into tiny cracks and offers a set with three different types of bristles.
Overall, wire brushes are a great tool to use when removing moss. You need to ensure you get rid of all the spores, so the brushes are best for getting hidden moss out of the cracks.
6. Use a Power Washer on the Cracks
Most slabs of concrete have some cracks in them. You can also use this method if moss grows in the gaps between cement pavers. A power washer should rip up any moss growing there easily. It’s a good option if you can’t fit a rake between the concrete cracks.
Power washers work by blasting surfaces with hot water using high pressure. Most unwanted plants can’t withstand it, including moss.
However, you’ll want to do this on a sunny day, so the water dries quickly. That way, the moss won’t return as fast.
If you don’t own a power washer, you won’t need to buy one. Instead, you can usually rent them from home improvement companies. Or, you could have a local landscaper come and use the power washer for you.
These tools are convenient and great for removing weeds and moss from concrete. You’ll want to ensure that you use the correct settings and don’t damage the cement.
Can Power Washers Worsen Moss Growth?
If you don’t use the power washer correctly, the water from the machine can cause the moss to grow back rapidly. You’ll want first to blast away all the large pieces of moss. Then, you’ll need to review all the crevices in the cement thoroughly.
Spores from the moss can linger in those cracks where there’s shade and a lot of water from the power washer. If you don’t remove the moss in the gaps, it will come back worse than before.
So, power washers are a very convenient and easy-to-use option for removing moss. Still, you need to be careful if you use this method.
7. Try Pouring Boiling Water on the Moss
Next, you can also try pouring boiling water onto the moss. The heat softens the moss and makes it easier to rake or pull up. This method is one of the easiest; many prefer it because it doesn’t involve chemicals.
The hot water can also flow into cracks in the pavement, so it’s great for reaching the tiniest gaps to remove the moss yourself.
Boiling water is a simple and effective method for removing moss. You can make it even more effective by adding a few splashes of white vinegar to the water right before pouring it over the cement. The hot water kills the moss, and the vinegar can help prevent it from returning.
You’ll need to use this method several times to get the best results.
What Causes Moss To Grow on Cement?
Certain conditions can cause moss to grow on cement. For instance, ample shade and water make it habitable for moss. However, some concrete use ingredients that make them more acidic, which moss likes.
Many concrete structures and surfaces are sheltered and moist, making them perfect environments for moss to thrive on. Concrete is also very porous, so the moss can attach to it easily and absorb water from the material if needed. All of these factors make it highly appealing to moss.
Before trying to remove the moss, you’ll want to inspect the conditions of the cement. It will keep returning unless you can change some of those conditions. For instance, if the cement is always moist, you’ll need to find a way to keep it dry to stop the moss from growing there again in the future.
In short, moss likes concrete for several reasons. Most of the time, concrete offers moss its ideal living conditions.
How Damaging Is Moss To Concrete?
Moss can be very damaging to concrete. Patches of moss are consistently wet, which makes the concrete slippery and dangerous to walk on. Plus, the water the moss holds in erodes the cement quickly. It will start breaking down and won’t last long.
Water from the moss can also get into cracks in the concrete, leading to more severe damage. These cracks can worsen, and you’ll need to pay for a concrete repair caulk to fill them in. If the damage is bad enough, you’d need to replace the entire slab of concrete. The cost adds up very quickly if it’s a driveway or sidewalk.
Overall, it’s much better to prevent moss and deal with it as soon as you notice it. Doing so can prevent a lot of damage to your concrete.
What Problems Can Moss Cause?
Moss can cause many problems, including obstructing runoff water, breaking down building materials, and becoming too heavy for structures to support it. Water is bad for any surface, and moss holds significant amounts of water.
Most problems caused by moss involve water damage in some way. It can block runoff water, leading to drainage issues. The standing water that builds up there causes problems since it can attract pests and kill plants through root rot. Plus, the moss can break down various building materials by keeping them constantly moist.
If you leave the moss for too long, it will become very heavy. This problem is a lot worse when moss is growing on your roof. It could crack your roof and lead to water getting inside, which would be extremely expensive to fix!
Lastly, many people don’t like how moss looks growing on their property. You’ll want to get rid of it quickly to avoid it causing any costly damage to your home.
To summarize, there are many ways to remove moss from your concrete. You can use multiple methods to get the best results. You’ll need to be consistent to ensure the moss doesn’t return, so you’ll want to clean out the crevices in the concrete as much as possible.