Fog has been identified as an important atmospheric process created by condensation of water vapor around particulate matter and plays a very complex role in ecosystems, particularly in drylands and semiarid regions. This chapter discusses the variety of fogs—radiation, advection, and upslope—characterized by different cooling mechanisms and discusses the impact of atmospheric aerosols on fog formation. It provides excellent contributions for water supply, plant growth, and nutrient uptake, relieving water stress within the ecosystems, whereas acidic fog formed due to pollution threatens plant health and soil quality. This chapter explains how the presence of fog promotes increased moisture supply to different classifications of plants: trees, shrubs, and grasses. These plant species positively respond to the fog that reaches them depending on the species and environment. For instance, tree species such as Aextoxicon punctatum and Pinus muricata favorably respond to the presence of fog, whereas shrubs like Artemisia californica perform well in coastal areas. Grass species Stipagrostis sabulicola are also influenced by water reaching the soil to survive under drought conditions. It also involves precipitation in soil moisture dynamics, productivity of the ecosystems, and nutrient cycling, especially in drylands where traditional rainfall is confined. While stimulating microbial action and nutrient deposit, it hydrates rare plant species. However, its capacity to carry pollutant fragments raises concerns for ecosystem health. This chapter discusses the modulation of fog on the physiology of a leaf and air quality and implications for plant adaptation to climate change. This chapter also provides an in-depth analysis of the metabolic responses of plants to fog and illustrates the impact of genetic modulations on their growth patterns. Fog, which has been proven, possesses a dual nature, being both a boon and a bane, ultimately culminating into a call for further research into its ecological consequences, especially within changing climatic conditions. Finally, it should become clear why this complex interaction between fog, plant systems, and soil health is crucial for the application of sustainable agriculture in a water-limited environment.