If white areas on the concrete pavement do not want to give way or if they return regularly, it is most likely a lichen infestation. Although the obscure plants disturb the overall picture, they can be combated with simple means.
What are lichens?
Lichen, also known as lichenes in botanical jargon, is a symbiosis of photoautotrophic organisms such as algae and fungi. They are mistakenly referred to in connection with green coverings and mosses. In this interaction, the fungus benefits from the products of photosynthesis, while the algae receive minerals, water and protection against dehydration.
The coral-like body usually consists of simple crusts or abstract structures that have a wide range of colors. In their own garden they grow on buildings, roof tiles and trees as well as concrete paving stones and stones. Overgrown trees usually do not experience any disadvantage from the vegetation. In other cases, the removal can be worthwhile to prevent damage or for visual reasons.
How do lichens arise on cobblestones?
Unlike verdigris or moss, lichens are created in a completely different way. The community of fungi and algae has no roots, it absorbs all nutrients from the air and the subsoil.
It is very characteristic of mushrooms that they reproduce via spores. Due to their extremely low weight, spores can be transported over vast distances by the wind in order to find suitable
Set up a colony. Not least because of this property, the removal of a lichen is like a Sisyphean task.
Even after removal with a wire brush or a scrubber, spores or tiny remnants of the fungus remain. The reproduction of the previously removed fruiting body takes place quickly. Only minimal requirements are required for the spores to germinate. Appropriate humidity and good air quality are sufficient for this.
Why is removal necessary?
Overgrown figures or natural stones are not damaged by the growth. Sometimes they give overgrown objects an old-romantic charm. However, the spores of the fungi involved can cause health problems in sensitive people. Removal of the infestation is also advisable in the case of overgrown driveways, terraces and sidewalks. In wet weather, the slippery and unsafe surface of lichens creates a significant risk of injury when wet. Last but not least, they synthesize organic acids, which they ultimately secrete to the subsurface. Paving stones and other floors are damaged and crumble as a result. There are cracks, stains and various damage to the substance.
Tip: Although a lichen growth conveys a romantic aesthetic depending on the case, removal is often advisable for safety reasons. Paving stones are particularly vulnerable and require regular cleaning for that
permanent elimination of the infestation, as the rough surface favors settlement.Removal materials
There are many different measures you can take to combat stubborn lichen. Different materials are used depending on the type of removal. The following is a short list of the tools:
- Scrubber
- Wire brush
- Wire broom
- high pressure cleaner
- Lichen remover
- Soda solution
- Biocides
Remove stains from paving stones
There are a variety of ways to stop fouling. The procedures include, for example:
Mechanical removal
Mechanical removal with a wire brush or a scrubber requires enormous effort and time. Often the superficial removal is sufficient if there is only a slight infestation. Aids such as high-pressure cleaners work wonders for cleaning up large build-ups.
The powerful devices shoot the mushroom from the stones with high pressure. Due to the high pressure, this method can only be used for compact stones. In the case of soft materials such as sandstone or lime, the surface would damage the stone as a result of the treatment and reveal further areas of attack for mosses and lichens.
Home remedies
Home remedies such as baking soda or fruit vinegar can also help with minor infestations.
Boiling water and baking soda
- The floor must be cleared of coarse dirt. You can do this with a simple broom.
- Depending on the area, sufficient water must be boiled and poured into a bucket.
- There are now about 30 grams of soda powder for every 10 liters of water.
- The solution must now be distributed to the affected areas and act.
- After 24 hours, the areas can simply be scrubbed off with a wire brush.
- Finally, the floor can be rinsed with water to remove the residue.
Info: Soda has two wonderful properties. While it simplifies the elimination of the lichens, it also offers long-term protection against the spores
and a renewed expulsion.Wine and fruit vinegar
- Vinegar essence is mixed with water in a 1:10 ratio.
- Use a watering can to spread the solution over the affected areas.
- After a short exposure time, the growth can easily be removed with a wire brush.
Tip: The use of biodegradable green film remover is simpler and less complicated. The products from the hardware store contain pelargonic acid and are environmentally friendly.
Caution: Care must be exercised when using aggressive home remedies such as a self-made baking soda solution. If they get into the environment, they can cause great damage.
Chemical process
An alternative is chemical removal. It is based on the use of biocides, which provoke decomposition of the structure and destroy fungal spores. Special active ingredients should provide long-term protection for the treated surface and kill spores that have settled. Corresponding products are also freely available in retail outlets for private individuals.
What mistakes should be avoided?
Among the numerous methods of lichen control there are also some that should be avoided for environmental reasons. Burning of lichens with a standard weed burner or conventional gas burner removes lichen completely, for example, but also harms useful plants and animals Space. The treated natural stone can also be damaged by the great amount of heat generated. Even when using a high-pressure cleaner, it is important to test in advance whether the treatment is also suitable for the stone floor in question. If the stone floor contains deep joints, the pressure can push the spores deep into the earth and thus accelerate resettlement.
Last but not least, numerous cleaning agents advertise that they can completely remove the uninvited growth. However, these products are often associated with numerous dangers. The very aggressive ingredients not only damage the environment, but also your own health and the surface to be treated.