Jennifer Schultz Nelson
Extension Educator, Horticulture
Mention growing Ficus, and many people assume you mean the houseplant that is a small tree native to Southeast Asia. But they're only partially right. Ficus is an enormous genus of plants containing over 800 species. Some species are trees, but others are shrubs and vines.
The common name for this genus is Fig, which does include the species Ficus carica, commercially grown to produce the fig which we enjoy fresh, dried, or processed in items like cookies. Dried figs have been shown to contain high levels of antioxidants, compounds that are increasingly linked to good health. Also, according to the USDA, 100 grams of dried figs contains 10 grams of fiber, the highest level found among fresh or dried fruits.
Evidence has been unearthed in Jordan showing figs were consumed as many as 11,400 years ago. Some historians argue that figs were probably one of the first if not "the" first domesticated crop.
Botanically, figs are both fascinating and somewhat confusing, particularly when discussing the fruit. They have evolved an interesting relationship with a tiny wasp that makes flashy flowers unnecessary.
If you were to look for a fig flower, you would not see a colorful bloom waiting to be pollinated. In fact, you can't see the flowers just by looking at the plant! Instead, you would see a knob-like structure that looks like a tiny fig. This structure is called a synconium. It is essentially a flower turned inside-out.
There is a tiny opening at one end called the ostiole which leads to thousands of tiny fig flowers lining the inside of the synconium. While we would commonly call the entire mature structure the fig fruit, technically speaking there are thousands of fig fruits, one per tiny female flower, hidden within the larger whole.
The tiny ostiole is the gateway to the many fig flowers, limiting what can effectively pollinate those flowers. Each species of fig has evolved a relationship with a specific species of wasp which is tiny enough to fit through its ostiole. The female wasp passes through the ostiole into the synconium to lay her eggs in the tiny fig flowers.
The fig flowers offer nourishment and protection for the developing wasp eggs and larvae. As the female wasp lays her eggs in the fig flowers, she brings with her pollen from male flowers of the fig tree from which she hatched, pollinating some of the female flowers in the synconium as she lays her eggs. When the eggs she laid hatch and develop into wasps, pollen from the male flowers in their synconium rubs off on the new wasps.
The newly hatched females mate with male wasps that also developed in the current synconium, then travel to a new synconium on another fig tree of the same species, pollinating the female flowers of that tree while laying eggs in a few of those female flowers as well. The male wasps never leave the synconium. They are just there to mate with the females.
Those flowers containing wasp eggs and later larvae will never develop seeds, but there are enough female flowers in one synconium that some can be lost to the wasp larvae without much harm to the plant.
As with many things in nature, there is always an exception to what seems like a pretty solid rule. There are actually two "sexes" of figs, and sometimes one tree can switch sexes! These are not the typical "male" only and "female" only flower producing plants that I've written about in other columns.
In the world of figs there are hermaphroditic plants which have synconiums containing both male and female flowers. This group is called the "caprifigs", whose fruit is not edible. The other group is made of species which have synconiums where the male flowers never develop, leaving only female flowers. Sometimes these synconiums can mature into edible fruits without pollination. This group is also called the edible figs.
Complicating matters is that some species and cultivars of edible fig will produce multiple crops per season, one needing pollination by the wasp, the other developing without pollination. Edible figs which have been pollinated develop a nutty flavor due to the seeds present.
While most edible figs prefer a climate with winters warmer than central Illinois, Ficus carica 'Chicago Hardy' is the cultivar most often recommended for our zone 5 weather. The plants produce most abundantly with some winter protection. My family had one of these fig trees, but I use the term tree loosely. We would mulch around it with straw each year, and it would die nearly all the way to the ground over the winter. It really looked more like a shrub. Miraculously, it was a pretty reliable producer of tasty figs.
Sometimes the Ficus species we grow as houseplants will form synconiums. I had a Weeping Fig, Ficus benjamina, that had branches covered in them one year. Since we lack the wasp species needed to pollinate the flowers inside, seeds never developed.
A common concern people have is when their Ficus tree loses leaves. This may happen quite suddenly and in great numbers. Ficus are native to parts of the world where there is a rainy season and a dry season. Typically when water is scarce in the dry season they will drop leaves as a survival mechanism, and quickly re-grow them when the water returns during the rainy season. If watering is erratic indoors, the tree may think the dry season is upon them! They will also drop leaves if watered too much, or in response to moving to a new location or being placed in a draft. If leaf drop is a problem with your Ficus, take a look at the environment and make changes if necessary.
There are other species of Ficus suited for indoor gardening. One familiar species is Ficus elastica, or the rubber plant. While not used to produce rubber, it does ooze a sticky, rubbery sap as do all Ficus. The dark, nearly black, thick glossy leaves also look as if they might be made of rubber.
Creeping fig, Ficus pumila, grows with very small leaves and aerial roots that enable it to cling to supports and climb. One niche where this plant performs exceedingly well is in topiaries at Epcot at Disney World in Florida. This plant seemed to be in every topiary I saw while visiting there last year. Staff commented that it was well-suited for topiary but sometimes grew a little too fast for the maintenance crew's liking!
With a little care, Ficus can live indoors for many years. They often grow very large, but can be pruned to keep them appropriately sized for the home. If your Ficus is looking less than perfect, don't despair. Assuming you give them bright light in your home and moderate moisture, they should rebound. My best Ficus benjamina started out as a plant that suffered for years in a dark corner at my friends' house. They were ready to throw it out, but I took it home just to see if I could save it. It had about ten leaves and three branches. With a little TLC and time, it has grown into a great looking plant that I keep in my office.