How to Clean Outdoor Furniture Before Storage

Storing dirty outdoor furniture is how you guarantee mold and mildew will colonize it over the winter. The season's grime—pollen, dust, bird droppings, salt spray if you're coastal, algae if you're shaded—all become feeding grounds for decay when furniture sits idle in damp storage. Clean furniture stored properly will emerge next spring ready to use, not requiring a full restoration. The goal is to remove all organic matter and moisture, then create an environment where nothing can grow on your pieces while they're out of sight.

1. Inspect and pre-treat stubborn spots. Walk each piece and identify problem areas—bird droppings, sticky sap, algae stains, rust spots. Pre-treat these with targeted solutions before full cleaning. Use a plastic scraper on dried deposits, a wire brush on rust, and a mildew remover on dark stains. Don't blast everything at once; targeted work now prevents aggressive scrubbing later that can damage finishes.
2. Wash wood and composite pieces. Mix warm water with a oxygen-based deck cleaner or mild dish soap. Use a soft-bristle brush or sponge to work the solution across all surfaces, paying attention to crevices, joints, and underframes where dirt accumulates. Rinse thoroughly with a garden hose on low pressure. Don't use a pressure washer on wood or composite—it strips finish and opens the grain.
3. Clean metal frames and hardware. For painted metal, use the same warm soapy water and soft brush. For bare aluminum or stainless steel, use a cloth-based metal cleaner to restore shine and prevent oxidation. For rust spots on steel, apply a rust converter or light steel wool with mineral oil, then wipe clean. Don't let corrosive cleaners sit; apply, work, and rinse immediately.
4. Address cushions and fabric. Remove cushions and wash covers according to fabric label instructions—most can be hand-scrubbed with mild soap and water, then rinsed. For mildewed fabric, apply a diluted vinegar solution (one part vinegar to three parts water) and let sit for 15 minutes before scrubbing. Wring out excess water but don't machine-spin dry. Stand cushions upright and lean them against a wall in full sun to air dry completely.
5. Dry everything thoroughly. This step determines whether mold grows or not. After washing, wipe down all furniture with clean towels, then leave everything in direct sun for a full day. Air circulation is critical—don't stack pieces together. Check undersides, crevices, and seat bases where water pools. Run your hand over every surface; if it feels slightly damp, it's not ready to store. In humid climates, leave furniture out for two days.
6. Apply protective finish if needed. For wood furniture, consider a water-based sealant or teak oil to prevent drying and checking over the off-season. For metal that showed any rust, apply a thin coat of spray wax or automotive protectant to repel moisture. Don't overdo this—a light coat is all that's needed. Let any finish dry completely per product instructions before wrapping or storing.
7. Wrap and store in a dry location. Once everything is completely dry, wrap pieces in breathable tarps or old sheets—never plastic, which traps moisture. Store in a shed, garage, or basement with good air circulation. Keep cushions in a sealed plastic bin with a desiccant packet. Elevate furniture off the floor on wooden blocks or shelves to prevent ground moisture absorption. Check the storage space for roof leaks, gaps where pests can enter, and standing water before you commit furniture to it.