Outdoor bronze sculptures are susceptible to biological patinas, which can mar their appearance and structural integrity over time. To preserve these artworks, several proven methods can be employed.

1. Regular Cleaning: Gently wash sculptures with distilled water and a soft brush to remove dirt, algae, and organic matter. Avoid harsh chemicals that may damage the bronze.

2. Protective Coatings: Apply microcrystalline wax or specialized lacquers to create a barrier against moisture and biological growth. Reapply every 6–12 months for optimal protection.

3. Environmental Adjustments: Position sculptures away from damp, shaded areas where mold and algae thrive. Ensure proper drainage to prevent water accumulation.

4. Biocidal Treatments: Use eco-friendly biocides to inhibit microbial growth without harming the bronze. Consult conservation experts for safe application.

5. Professional Maintenance: Schedule annual inspections with conservators to address early signs of patina and apply advanced preservation techniques.

By combining these methods, you can significantly reduce biological patina formation and extend the lifespan of outdoor bronze sculptures.