How to Remove Mildew from Outdoor Furniture

Getting your outdoor area ready for warmer weather is always a good feeling — until you notice that stubborn film of mildew on your furniture. Mildew can form quickly after rain, humidity, or long periods without airflow, and it can make even the nicest outdoor setting look tired.

The good news: you can remove mildew from most outdoor furniture with a few basic tools and the right approach for each material. This guide covers how mildew forms, how to clean it safely, and how to reduce the chance of it coming back.

What Is Mildew and Why Does It Grow on Outdoor Furniture?

Mildew is a type of mould that tends to grow on the surface of materials, especially where there’s persistent moisture and limited airflow. Outdoors, that often means furniture that stays damp after rain, is stored under covers without ventilation, or sits in shaded areas where moisture doesn’t dry quickly.

Mildew spreads via microscopic spores that drift through the air and settle on surfaces. When the conditions are right — moisture + warmth + organic residue (like dirt, pollen, body oils, or leaf debris) — mildew colonies can take hold surprisingly fast.

If you want a quick primer on identification, this guide explains mildew vs mould and how they differ.

Before You Start: Safety and Setup

Mildew removal is straightforward, but take a few precautions — especially if the growth is heavy or you’re sensitive to mould.

• Work outside in fresh air.
• Wear gloves and consider a mask if mildew is widespread.
• Brush off dry debris first so you’re not scrubbing grit into surfaces.
• Test any cleaner on a hidden spot before treating the full area.

General Mildew Removal Method

Regardless of the material, this process works as a starting point:

1. Dry-brush first: remove loose surface growth and dirt.
2. Apply a cleaner: spray or sponge it onto the affected area.
3. Let it dwell: give it a few minutes to break down the mildew.
4. Gently scrub: use a soft brush or sponge (avoid harsh scouring pads).
5. Rinse thoroughly: remove residue so it doesn’t attract more grime.
6. Dry completely: mildew returns fastest when furniture stays damp.

Best Cleaning Solutions for Mildew

Choose one of these based on what you’re cleaning:

• Mild soap + warm water: safe for most surfaces and good for light mildew.
• White vinegar + water (1:1): effective on many outdoor materials and fabric-safe for most colourfast textiles.
• Oxygen bleach (not chlorine bleach): useful for stubborn staining and many outdoor fabrics (always patch test).

Chlorine bleach can work on some surfaces, but it can also weaken fabrics, damage stitching, and discolour finishes — so it’s usually a last resort.

How to Remove Mildew from Different Outdoor Furniture Materials

Wood Furniture (Including Teak)

Wood can hold mildew in grain and texture, so the goal is to remove growth without stripping the finish.

• Mix warm water with mild dish soap, or use a 1:1 vinegar and water solution.
• Scrub gently with a soft brush in the direction of the grain.
• Rinse and dry thoroughly.

If mildew is severe and the wood is unfinished, a specialised wood cleaner may be more appropriate. After cleaning, letting wood dry fully in sunlight helps reduce lingering spores.

Wicker Furniture

Wicker is tricky because mildew hides in gaps. Avoid soaking it for long periods, especially if it’s natural wicker.

• Dry-brush first to remove loose growth from crevices.
• Use a spray bottle with vinegar solution or mild soapy water.
• Scrub with a soft brush and use gentle water pressure to rinse.

Don’t blast natural wicker with high pressure — it can fray fibres and loosen the weave. For resin wicker, you can rinse more confidently.

Metal Furniture (Aluminium, Steel, Wrought Iron)

Mildew usually grows on grime sitting on the surface rather than the metal itself.

• Clean with warm soapy water or vinegar solution.
• Wipe or lightly scrub, then rinse and dry.

If you notice paint flaking or rust forming, address that separately to prevent further damage.

Plastic Outdoor Furniture

Plastic is one of the easiest materials to clean — the challenge is avoiding harsh scrubbing that dulls the finish.

• Spray with mild soapy water or vinegar solution.
• Let it sit for 5–10 minutes.
• Scrub with a soft brush and rinse clean.

For stubborn staining, oxygen bleach can help, but always test first to avoid patchy discolouration.

Outdoor Cushions and Fabric Furniture

Fabric holds moisture, so speed matters — treat mildew early before it stains or penetrates deeper layers.

If the covers are removable, follow the care label and wash with mild detergent. If they’re not removable:

• Dry-brush mildew off the surface first.
• Spray with a 1:1 vinegar solution or mild soapy water.
• Gently scrub using a soft brush.
• Rinse lightly and allow to dry completely in sun and airflow.

For a deeper step-by-step method on textiles, see how to remove mould from fabric.

How to Prevent Mildew from Coming Back

Once you’ve cleaned everything, prevention is what saves you from repeating the process a few months later.

1. Dry First, Store Second

Never store damp cushions or furniture covers. Even slightly damp fabric can create a mildew-friendly microclimate inside storage boxes, under covers, or in sheds.

2. Improve Airflow

Mildew thrives in still, humid air. Try to:

• Leave space between furniture and walls/fences.
• Avoid tight covers that trap moisture.
• Open storage boxes regularly to release humidity.

3. Clean More Often Than You Think You Need To

Mildew feeds on organic residue. Regular light cleaning makes it harder for spores to gain a foothold.

4. Choose Outdoor Materials That Resist Moisture

Outdoor fabrics vary massively in performance. Materials designed for wet-zone use and UV exposure are less likely to hold moisture and break down over time. If you’re choosing seating that lives outside, purpose-built options like outdoor bean bags are designed to handle weather exposure better than standard indoor textiles.

5. Understand Waterproof vs Water-Resistant

Not all “outdoor” materials behave the same. Some resist splashes but still allow moisture to seep in over time. If you want to understand the difference (and why it matters for covers and cushions), see waterproof vs water-resistant fabric.

Final Tips

• Act early — light mildew is easier to remove than established staining.
• Always patch test cleaners, especially on fabrics and painted finishes.
• Dry thoroughly after cleaning to prevent immediate regrowth.

Mildew can be frustrating, but it’s manageable with a consistent approach. Clean it properly once, improve airflow and drying habits, and you’ll keep your outdoor area looking fresh far longer.