Getting Rid of Lichen on Wooden Deck: A Homeowner’s Guide

Wooden decks are a perfect place to relax, but they’re also magnets for growths like moss, algae, and lichen on wood. While lichens are harmless to humans, they can make your deck look aged, create slippery patches, and slowly damage the wood if left untreated. If you’re wondering about getting rid of lichen on wooden deck, this guide covers safe removal, cleaning methods, and prevention.

What is lichen on wood?

Lichen is a mix of algae and fungus living together. It thrives in shady, damp conditions, often appearing as greenish-gray patches with a crusty or leafy texture. Unlike moss, it doesn’t have roots, but it clings tightly to porous surfaces like wood.

The Royal Horticultural Society notes that lichen itself doesn’t directly harm wood, but it traps moisture that may lead to rot over time.

Lichen won’t eat through your deck, but it creates a damp environment where decay sets in faster.

Lichen growth on wooden deck

Getting rid of lichen on wooden deck: step-by-step

Step 1: Prep the surface

• Sweep the deck to remove loose dirt and debris.

• Wet the surface lightly with a garden hose.

Step 2: Choose your cleaning solution

Safe and effective options include:

• White vinegar: Natural and eco-friendly, mixed 1:1 with water.

• Oxygen bleach (sodium percarbonate): Safer than chlorine bleach for plants and pets.

• Commercial deck cleaners: Formulated for outdoor wood and usually lichen-friendly.

Step 3: Scrub the lichen

• Apply the solution and let it sit for 10–15 minutes.

• Use a stiff-bristle brush (not metal) to scrub the patches.

Step 4: Rinse thoroughly

Rinse with a garden hose to remove residue. Avoid pressure washing at close range, which can damage wood fibers.

Step 5: Let it dry

Allow the deck to dry completely before applying sealers or treatments.

The EPA recommends oxygen-based cleaners for outdoor surfaces because they break down safely and don’t harm nearby vegetation.

Skip chlorine bleach unless absolutely necessary—it can discolor wood and kill surrounding plants.

How to prevent lichen on wood

• Seal your deck every 1–2 years to reduce moisture absorption.

• Trim nearby trees to increase sunlight and airflow.

• Keep the deck dry by sweeping off leaves, soil, and debris.

• Regular cleaning with mild soap and water prevents buildup of spores.

Clean wooden deck after lichen removal

FAQ

How do I remove lichen from a wooden deck?

Scrub with vinegar, oxygen bleach, or a deck cleaner, then rinse thoroughly.

Will lichen damage my deck if left untreated?

Yes—while lichen doesn’t eat wood, it holds moisture that can accelerate rot.

Is pressure washing safe for lichen removal?

Yes, but only at a low setting. High pressure can gouge wood fibers.

Can I prevent lichen on wood naturally?

Yes—regular cleaning and sunlight exposure reduce lichen growth.

Is vinegar safe for removing lichen on wood?

Yes, vinegar is a safe and effective natural solution.

Final verdict: keeping your deck lichen-free

When it comes to getting rid of lichen on wooden deck, the best method is a simple one: scrub with vinegar or oxygen bleach, rinse, and seal the wood for long-term protection. With regular maintenance and proper airflow, your deck will stay safe, clean, and inviting for years to come. 🌞🪵