Cacti are incredibly sturdy plants, able to survive tough conditions and adapt to hostile environments. Yet they still need certain elements to remain healthy, most notably sunshine.
Most cactus species require a minimum amount of direct sunlight each day in order to thrive and grow. Without enough light, a cactus can begin to weaken and eventually die.
The sun gives the cactus life-sustaining energy for photosynthesis, necessary for both growth and survival. The duration of shade the plant can tolerate varies by species; some types can handle up to seven hours of shade daily, while others require full sun — six or more hours with no less than 90% exposure. Cacti are remarkable plants for what they can endure. While most plants require light and water to survive, cacti have adapted to the harsh environments of deserts and other arid conditions in which many plants cannot survive.
Without sunlight, cacti still manage to draw energy with their photosynthesis process — even though it runs at a much slower pace than typical photosynthesis in other plants that get regular access to direct sunlight. They also have developed various ways of storing water, such as adapting a waxy outer layer that has incredible water retention capabilities, allowing them to remain hydrated without the sun or water.