Lichen control involves managing the growth of lichen, a symbiotic organism made up of fungi and algae. While lichen can be harmless, it may indicate underlying issues such as poor air quality or excessive moisture. Effective control methods include improving air circulation, reducing moisture levels, and using chemical treatments when necessary. Preventive measures are also important in lichen control. Regular maintenance of surfaces, such as roofs and sidewalks, can help minimize lichen growth. Additionally, choosing appropriate plants and landscaping techniques can reduce moisture retention, further limiting the conditions that favor lichen development.