The answer to 'why is my upholstery mildew' is that mildew can grow on upholstery due to excess moisture, poor air circulation, or lack of cleaning. Mildew thrives in warm, damp environments and can discolor and damage fabrics over time. Common causes include spills, humidity, and not allowing upholstery to fully dry after cleaning.
If you notice mildew on your upholstery, it's important to address the issue quickly to prevent further damage. Start by identifying and addressing the source of the moisture, such as a leaky window or high humidity levels in your home. Then, thoroughly clean the affected areas using a mildew-killing solution and allow the fabric to fully dry. In some cases, you may need to replace severely damaged upholstery.