Shaded walls are protected by buildings, overhangs, trees, staircases, narrow streets, or retaining-wall structures. In Hong Kong’s hot, humid, and rainy summer, these walls may stay damp for longer, especially when they are near drainage pipes, water stains, stair edges, or cracks. They can support more moisture-associated growth, such as fern-like plants, moss-like growth, small herbs, or seedlings growing from cracks. Additionally, some of these walls can also get some sunlight during certain times of the day therefore giving them a perfect environment to grow in. However, shaded walls are not always cool, because poor airflow between buildings can make them warm and humid.
