By Jerry Meislik
One of my favorite trees for indoor bonsai is the Chinese Banyan, scientific name is Ficus microcarpa. In the tropical foliage trade the same tree is called Ficus nitida or microcarpa. In this article I will refer to it as Ficus microcarpa or the Chinese banyan. The Chinese banyan is very widespread and found in landscapes and as a container tree in many countries of the world. It is used for boulevard trees in many cities including those of southern California.
The tree is ideal for indoor growing, tolerating a wide range of indoor conditions and surviving. It has good tree character with reasonable sized leaves, strong rootage and good twigginess, all making for a believable bonsai. Additionally the leaves reduce under typical bonsai culture, and the plant forms aerial roots with relative ease.
Common names and varieties of this fig are Indian Laurel, Green Island, Green Gem, Green Spire, Green Emerald, Green Mound, Tigerbark, Hawaii, and Nitida, Chinese Banyan, Ficus microcarpa, Ficus 'Ginseng', Ficus hillii, Malayan Banyan, Ficus crassifolia, Ficus Long Island, Tigerbark Fig, Kin Men Fig and many other names.
All these are varieties of Ficus microcarpa and show some variation in the bark or leaves from the typical tree.Natural Examples
The Chinese Banyan originates from Southeast Asia, and exists from India to Borneo. In nature it attains a height of 50 to 60 feet. Animals eat the figs and deposit their droppings, planting figs everywhere imaginable.
At Fairchild Gardens, Florida USA, it forms a large tree with many aerial roots, and grows in typical Ficus style with a single major trunk which quickly divides into multiple branch-trunks that arch up and contribute to a broad canopy. In moist areas the main trunk is surrounded by smaller accessory trunks that grow from aerial roots.
Leaf size shape and texture is quite variable from plant to plant with a typical leaf being elliptical and mildly pointed and about 4 inches long. Compare this to a Ficus benjamina leaf which has a longer tip and whose leaf is thinner in texture. The ‘Green Island’ variety has a much thicker, and rounder leaf than the normal variety.
In Taiwan I viewed three different clones of Ficus microcarpa with leaf size varying from small, medium, and normal. The smallest leafed forms are not used for bonsai due to poor trunk development but are used as graft material to place smaller foliage onto large trunked Ficus specimens. The smallest leaf form is called “Melon Seed” and has a yellowish green leaf color.
The bark on typical specimens is smooth and gray in color and very reminiscent of an animal skin. Some plants have mottled spots of white or gray on the bark. The Tigerbark form shows stripes of white superimposed on the background bark color. This variety also called Kingman or Kin Men was discovered in Taiwan over 35-40 years ago.
All Ficus microcarpa varieties have a bark that is thin and easily marred. With careless wiring the bark can be scarred and it can take many years for it to outgrow the scars. One tree that I have had for over 13 years has not outgrown its wire scars yet!Fig Fruit
Figs on Ficus microcarpa are about 1/3 to 1/2 inch in diameter, starting out green and maturing to a red or even almost black color. I have tasted them and they are not tasty but birds eat all the ripe fruit as soon as it colors up. Seed on indoor trees will not be fertile due to the absence of the fig wasp that is needed to pollinate the figs and to form fertile seed. In Florida I noted seedling microcarpas developing under adult microcarpa. The special fig needed for fertilization must have been introduced or a similar insect may be playing the same role.Aerial Roots
Chinese banyan will readily form aerial toots given the right conditions. Aerial roots form most easily under a heavy foliage canopy, moisture on the stems and with high atmospheric humidity. Given these conditions a profusion of aerial roots will form.
Depending on one’s tastes aerial roots can be removed, or retained and allowed to mature. In this way a banyan style tree with pillar roots and secondary trunks is developed. In Taiwan aerial roots and secondary trunks are not in much favor.
As with all bonsai design there can be too many roots, or roots that do not fit the overall pattern. Established aerial roots may be moved, wired, or shaped to suit the design.
Chinese banyans can easily be propagated from cutting of stems. I have not been successful in getting root cuttings to sprout. Air layers are also quite easy to accomplish. Fertile seed is available from some tropical seed sources.
Ficus microcarpa is becoming more available each year, and many greenhouses carry the material for indoor foliage use. These trees are easily reduced back to bonsai proportions. Bonsai dealers are importing them in increasing numbers due to their vigor and availability from Southern China and US sources.
I have been growing a number of Ficus microcarpa for years and have been very happy with their ease of culture and responsiveness to growth under metal halide lights.
Microcarpa In Other Countries
I have to say that based on my travels, Taiwan is the mother lode of Ficus microcarpa. In Taiwan there are Ficus clubs, Ficus exhibitions and Ficus books. I have been to Taiwan several times and I am always delighted at the large number, large size and quality of the Ficus trees.
As with any indoor bonsai the Chinese Banyan will do best in bright light, but it will also survive under fairly low room illumination.
For the best results grow the tree in the brightest location in your home and if possible augment the room illumination with artificial light. Even fluorescent lights placed close to the foliage will be a great help in keeping the tree healthy and vigorous.
All figs appreciate even moisture at the roots. Allow the soil surface to dry a bit before watering again. Roots kept constantly wet will rot.
Water quality in terms of pH and hardness are not critical to the fig. Tap water that is adequate to grow other houseplants will work well for the Chinese banyan.
Use any well draining bonsai soil, but avoid soils that stay wet for days at a time. The trees can be grown in any mix from 100% inorganic, to 100% bark chips.
Use any brand of houseplant fertilizer, and use it at half strength every week while the tree is in active growth. Once the fig rests in the fall allow it to go without fertilizer. Never fertilize a sick or dry fig.Insects/Diseases
Few bugs seem to bother vigorous fig trees. But occasionally insects may invade.The most common insect is scale. They look like dark brown or black waxy bumps on the leaves and stems and can be removed with your fingernail but to achieve a “cure” use dormant oil at 1 tablespoon per gallon applied to all tree surfaces at 5-7 day intervals for 4 sprayings.
Thrips are a pest that seems to bother figs in tropical climates. They are found in the distorted and rolled up leaves at the branch tips. Thrips seldom seem to be a problem in figs grown indoors.
Mealy bugs may also be an occasional invader that can be treated with appropriate insecticide sprays.
Trees will need to re-potted every two to three years or if the tree show roots circling the pot. Generally repot when the tree is in very active growth. Remove all the old soil and replace with fresh bonsai soil. Water carefully until the tree re-establishes. Less water will be needed in the first two weeks after a potting. Do not put the newly potted trees into sunlight but allow two weeks in partial shade for adaptation.
Many fig owners will put their trees outdoors for the summer. This allows the trees to benefit from increased light, and great air circulation. This outside vacation period may be extremely critical in getting the tree back to health and subsequently to survive the coming winter indoors.
Insect invasion is a strong possibility when trees are outdoors. Other dangers include sunburn, wind, and other damage. Remember to place your trees so they get only partial shade for the first two weeks outdoors and to keep the tree away from large overhanging branches and neighbor’s animals that can damage the tree. Examine and treat the tree before bringing it back indoors to prevent insects from traveling back into the home.Temperature
Remember to move your trees inside when temperatures drop below 55 Fahrenheit or your trees may suffer long-term damage,
The Chinese Banyan is one the finest trees for indoor bonsai, and tolerates a wide range of indoor conditions. It has good bonsai character, lovely gray bark, and superb basal root flare. It tolerates the beginner’s efforts and still makes a superb addition to the advanced bonsai grower’s collection. Try it and you will not be disappointed.