How to remove moss and lichen (wall terrace and other) ?

Helping humidity, mosses and lichen end up colonizing a facade, a terrace or any exposed surface. If left to their own devices, they attack the materials and become encrusted everywhere. But how to eliminate them? You need a little elbow grease and products capable of overcoming it. In addition to the chemical solutions that you will find on the market, we offer you some natural and economical recipes that have proven their effectiveness…

Always start by removing the biggest

Before using a specific product, it is better to do a first mechanical cleaning. Arm yourself with a push broom or a stiff brush to scrub the moss or lichen, on the ground or on a wall. If you are dealing with a thick layer of foam, this is an essential step. Without a first muscular cleaning, no product would come to the end. In more difficult to reach places, use a knife to cut the foam. Be careful not to damage the surface though. After eliminating the largest, remove the residue with a classic broom.

Before starting an anti-foaming operation, make sure the surface is dry. Outdoors, it is better to plan to work with three days of sunshine in front of you. In dry weather, mosses and lichens will more readily absorb the product you plan to use. And after the treatment, always take the time to rinse the surface, even for organic and natural products.

baking soda or vinegar to remove

You certainly have these products in your cupboards. Versatile and economical, do not hesitate to use them to fight against these undesirable plants.

Baking soda

Imagine that it is very effective in neutralizing invasive mosses and lichens. It combines the advantages: economical, easy to use, it cleans very well and poses no risk to the environment.

The method : In a bucket, prepare a mixture of 3 liters of boiling water and the equivalent of a cup of baking soda. With a push broom, scrub the surface with the mixture. Leave on for at least two or three hours before rinsing with clear water. Rinse thoroughly!

You can replace baking soda with soda ash. You will achieve the same result by mixing 2 tablespoons of crystals for a liter of hot water. In case of stubborn foam, you can directly sprinkle the soda crystals on the floor and scrub with the push broom.

white vinegar

Another versatile and economical product! It works wonders to neutralize moss, but be careful not to use it on certain materials. On stone or marble surfaces, it is better to forget about it.

White vinegar is used pure. It is sprayed directly at the level of the roots, preferably in sunny weather. Rinse generously with clear water.

Starch to unclog

But where to find starch? Nothing could be simpler: in the cooking water of your pasta, rice or potatoes! Don’t smile, it’s really effective. Spray the hot cooking water, soaked in starch, on the foam to be eliminated. Just let it act for a few hours, before scrubbing with a brush.

This solution is suitable for almost all materials. Starch unclogs mosses, lichens and even fungi with formidable efficiency.

Coarse salt for burning

If you place coarse salt at the foot of the roots, the moss or lichen will burn in place and will not grow back. For best results, dig a little at the root and fill this small hole with coarse salt. Rinse quickly.

If you don’t have too much time, put a handful of coarse salt in 3 liters of very hot water. Spray this mixture on the terrace and rinse quickly with clean water.

This method is suitable for horizontal surfaces, such as a terrace or the flagstones of a driveway. The surface will be sterilized; little chance that the foam will reappear for a long time. Be careful, avoid spraying your favorite plants, they may not survive this treatment.

citric acid to dry out

Don’t be put off by its name. This product present in citrus fruits (mainly lemon) is perfectly natural and biodegradable. Effective on all surfaces, it acts by drying out invasive plants. Care should be taken not to use citric acid on certain materials which could discolor under its action. This is the case of granite, marble or terracotta.

Its effectiveness is enhanced if combined with other products. Here is a recipe extremely effective: 300 g of citric acid, 10 ml of vegetable oil (rapeseed, sunflower, etc.), 75 g of baking soda and a few drops of tea tree essential oil. Add four liters of lukewarm water and mix everything. Spray this solution on mossy surfaces. Leave on for two to three days; expect good weather, it should not rain. It is then time to scrub the mosses with a push broom. Finish by rinsing with clear water.

Solutions for smothering moss

To eliminate certain invasive plants, smothering is a simple and effective method. It is enough to cover the mosses or lichens with a product intended to prevent them from seeing the light.

Packaging cardboard, carpet scraps

Take advantage of your old boxes or pieces of carpet to cover the areas invaded by moss. Secure everything well with a few large stones and leave this cover in place for several days. Deprived of light, the mosses wither very quickly. You still have to rub the result with a push broom to eliminate the residue of invaders.

Wood ash, flour…

The principle is the same. This time it’s a powder product that will prevent the mosses from seeing the light again. The ash of cold wood can be sprinkled on the foam. You need a good thickness, at least 3 cm. The plain flour corn gluten meal is also known for its effectiveness. You can also use sawdust ; as for the ash, plan a layer at least 3 cm thick.

Natural: black soap and basil essential oil

Naturally insecticidal and weedkiller, basil essential oil is your ally in the fight against mosses and lichens. The best is to associate it with black soap. Hot water, a little black soap and a few drops of basil HE, and you have a recipe for shock. Spray this mixture directly on the plants. Leave for a few hours and scrub with a push broom.

Other recipe : the black soap can also be used with an organic dishwashing product, the two being mixed in 3 liters of water. Dip the push broom into the bucket and scrub the mosses with it. Leave half a day of rest before brushing again, then rinsing with clear water.

Another natural product? the angelica manure, obtained by maceration (1 kilo of angelica for 10 liters of water). Pour it over the mousse and leave to act.

To strip, put the pressure!

If you are a fan of strong solutions and you have a high-pressure cleaner, here are two effective solutions for eliminating moss.

The high pressure jet

Use the pressure washer with water, without adding any product. The pressure of the water comes to the end of the best encrusted plants. You will still need a lot of water if you are treating a large terrace or a facade. Be careful not to use this method on an old or fragile surface.


This technique is so formidable that it is better to entrust it to a professional if you are not sure of yourself. Again, the pressure washer is useful. It is used to throw sand (or a pickling powder) on a surface to loosen lichen or moss. The risk is to damage or weaken the plaster of a facade. But when mastered, this technique is spectacular. The surface must then be treated with a water-repellent product to prevent the return of moss.

Chlorine products: in moderation

Of course, there are chemicals designed to kill mosses and lichens. If natural methods are far preferable, these products also have their effectiveness. The important thing is to dose them with caution and to respect the supplier’s instructions.

Chlorinated products are ready to use. Super concentrated, they spray on plants to saturate them. We let it act for a day; the next day, rinse with a jet of water. A brush broom then allows you to remove the residue.

Pay attention to your safety : protect yourself before using these chlorine-based products. Also protect the plants located near the area to be treated. Be careful not to spray this product on a fruit tree!

If mosses and lichens colonize natural surfaces in your garden, such as tree trunks, let them live. These plants are harmless and harbor microorganisms that birds love. Considering their ability to absorb CO2, mosses and lichens know how to be very useful to their environment.

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