Removing green algae in winter: the best method
Removing green algae in winter calls for an adapted approach. Read what you need to keep in mind.

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Removing green algae in winter may seem like a challenge, but with the right approach it is very doable. The damp, cold winter months give moss and algae the chance to grow on your wooden deck, terrace or garden furniture. This makes surfaces slippery and unattractive. Fortunately, there are proven methods to get your garden clean again. In this article, you will read how to remove green algae without damaging the surface, and how to prevent it from coming back quickly.
Video: Removing green algae in winter
In this video you will see how to remove green algae from wood.

Groene aanslag verwijderen: hoe verwijder ik groene aanslag?
Step-by-step plan: removing green algae in winter
Green algae can build up quickly in the winter months, but with this proven method you can remove it in no time:
Choose a suitable cleaner
An effective cleaner is essential for a thorough clean. Osmo Terrasreiniger removes green algae without damaging the surface, so your wood lasts longer.

Dilute the Osmo Terrasreiniger
The right dilution depends on how dirty the surface is:
Light green algae: 1 part Terrasreiniger to 25 parts water
Heavy green algae: 1 part Terrasreiniger to 1 part water

Scrub the surface thoroughly
Use an Osmo patio brush to remove the algae. Work in the direction of the wood grain.

Let the product work
Give the product 10 to 15 minutes to work, so the green algae loosens and comes away from the surface.

Rinse with clean water
Use a garden hose or a bucket of water. Do not use a pressure washer, as it can damage the surface and cause green algae to return more quickly.

Let the surface dry thoroughly
Prevent new green algae by making sure water drains away well, so it does not pool and moss and algae have less chance to grow.

Benefits of Osmo Terrasreiniger
✔ Powerful cleaning without damaging the surface
✔ Economical: 1 liter of cleaner is enough for 30 to 100 m²
✔ Suitable for wooden decks, fences and garden furniture
Tips to prevent green algae
- Make sure water drains away well, so it does not pool on your tiles or deck.
- Place your deck in a sunny spot, because sunlight slows the growth of moss and algae.
- Do not use vinegar, salt or chlorine, as these products can damage the surface.
- Treat your deck with a protective coat, such as Osmo Terras-Olie for wood or Osmo Steen en Terracotta Olie for stone, so green algae has less chance to grow.
Supplies
Besides these products, you will also need a bucket of water or a garden hose.
Preventing green algae from coming back
Want to prevent green algae from coming back quickly? Treat your deck with a protective coat after cleaning:
Wooden surfaces (vertical wood): Osmo UV-Beschermingsolie
Wooden surfaces (horizontal wood, such as decks): Osmo Terras-Olie
Tiles and stone surfaces: Osmo Steen en Terracotta Olie
Let the surface dry for at least 24 hours before applying the protective coat.
Maintenance advice
- Clean your deck at least twice a year to remove green algae.
- Make sure water drains away well, so there is no standing water.
- Use Osmo Terrasreiniger for an effective, gentle clean of your wooden surfaces without damaging them.
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