Ficus trees or fig trees form one of the largest genera of flowering trees, with more than 800 species. Ficus trees remain popular but challenging trees to grow indoors, in part because of their native tropical habitat, which in part explains their sometimes frustrating responses to the growing conditions provided for them by their caretakers.
Ficus trees are tropical plants, and most species live in the jungle. Tropical forests pose numerous challenges to the flora living there, notably the lack of light available to plants that cannot grow tall enough to reach the canopy. The most common ficus tree kept as a houseplant, Ficus benjamina, reaches 30 to 40 feet in the wild and is adapted to survive uncertain light conditions in the dense tropical forest.
Ficus trees are found throughout the world. According to Palomar College's website Wayne's Word, nearly every continent and island in the tropics has at least one native ficus species, and even small islands may have several. In the United States, ficus trees occur naturally only in Florida and Puerto Rico. Notably, the Hawaiian Islands do not have any native ficus species.
Unlike temperate regions of the world, the tropical habitats where the ficus naturally grows do not experience seasonal temperature fluctuations. They do, however, experience wet and dry seasons, and the ficus has adapted to survive those. Just as temperate deciduous trees shed their leaves as winter approaches, the tropical ficus sheds its leaves as the dry season approaches. Since most water loss occurs from a plant's leaves, losing its leaves helps the ficus survive extended periods of time where little water is available.
Adaptations such as leaf loss explain how the ficus can survive in a challenging tropical environment. Ficus trees also grow differently depending on the availability of light. Ficus trees that grow in the shaded understory of the jungle develop spreading branches that lets the tree benefit from the small patches of light that make it through the thick canopy overhead. Ficus trees growing in direct light, in contrast, assume a more upright growth. In the wild, ficus trees also have the startling ability to develop aerial roots. Ficus seeds germinate in the tops of other trees, and the roots grow downward, toward the ground, wrapping the trunk of the host tree as they grow. Eventually, such ficus trees will strangle the host tree.
The habitat and adaptations to that habitat of ficus trees inform their care as houseplants. Changes in light or water often causes the ficus to lose its leaves, a tendency that frustrates many a ficus tree owner. In the wild, leaf loss helps the tree to preserve its water. Ficus tree owners should keep environmental conditions steady in order to avoid leaf loss.