The genus Ficus is a large group of trees known as the figs. There are an estimated 1,000 different species, most of which come from tropical areas. The edible fig is the species Ficus carica. The others also produce fruit, but it is usually eaten by birds and animals. They are highly decorative and make a great houseplant or landscape tree in warm climates.
Many types of tropical ficus trees start their life as a seed that is deposited in the branches of another tree by a bird. They then germinate and grow aerial roots down the trunk of the host tree to the ground. When they touch the ground they take root and begin to shade out and literally strangle the host tree. These are called strangler figs. Eventually they kill their host and can even stretch out to envelope nearby trees. Not all tropical ficus trees are stranglers. Some put out aerial roots but are less intrusive. Others, like the creeping fig (F. pumila), cover the ground like a vine.
The fruit of a tropical Ficus is actually a modified hollow stem called a syconia, with the flowers on the inside. When it is immature, it is small and hollow with a tiny hole at the end. This hole is for a female wasp to enter the fig and lay her eggs. When the eggs hatch, the male and female wasps mate immediately. The males then die and the females make their way out of the now ripening fig collecting pollen along the way. The females then fly to a new fig, enter, lay their eggs and transfer the pollen to a new flower.
Large tropical ficus trees, like Indian banyan (F. benghalensis), that put down many aerial roots and can spread over huge areas are only suitable for large open places like parks. Ficus trees that tend to have single trunks are better for home landscaping, such as the Moreton Bay fig (F. macrophylla).
Outdoor grown ficus trees need tropical temperatures that never receive frost, although some varieties may be a little more cold tolerant than others. They benefit from humidity and may not produce as many aerial roots if the humidity is too low. Plant them in areas where they receive full sun, although young trees can tolerate shade. They are not too picky about soil as long as it is well draining and receives enough moisture to keep it from drying out completely.
The most popular indoor grown tropical Ficus tree is the weeping fig (F. benjamina). It has small, glossy green leaves about 2 inches long and only produces a few aerial roots. Often these trees are sold with elaborately trained trunks that are twisted or braided.
Indoors tropical ficus trees need bright filtered light from an east, west or shaded south exposure and stable temperatures. Cold drafts or sudden environmental changes will cause leaf drop. A rich, well-draining soil is best. They prefer to dry slightly between waterings but not dry out completely.
Tropical ficus trees produce a lot of fruit, which is important to animals and birds. Large old trees can cover several acres with numerous trunks and create a habitat of their own. In some areas, like southern Florida, strangler figs can damage roadways and kill native trees.