Ficuses: the Workhorses of the Interior Landscape by Paula Szilard Since the latter part of the nineteenth century, few plants have put in a more frequent appearance in our homes and offices than members of the genus Ficus. There are over 800 species in this genus, which includes the weeping fig (Ficus benjamina), the banyan tree (Ficus benghalensis), the Bo tree (Ficus religiosa), the rubber tree (Ficus elastica) and the common edible fig (Ficus carica). Members of this genus are often used in our interior landscaping because they can be pruned easily into tree-like shapes and add height and structure to our indoor plantings. In nature, though, they are sometimes stranglers, starting out as epiphytes on branches or crotches of trees, but eventually growing so large that they strangle their host. Ficuses have remained popular since they were introduced in Victorian times because they have many attributes which make them suitable for indoor culture. Though most grow under high light conditions in nature (often full sun), they adapt well to the reduced light levels available in our homes. The rubber tree, Ficus elastica, can be sustained for long periods on about 250 foot candles, although about 4,000 to 8000 foot candles are desirable for good growth. (As a point of reference, on the dreariest, most overcast winter day in Colorado, a measurement taken at the glass of an east or west window is roughly 300 f.c. and the measurement on a sunny winter morning at an east window is over 5000 f.c.) Still popular, though losing ground to its more attractive cousins, the rubber plant was a favorite in the Victorian home. Though all ficus species release a type of milky latex when wounded, only the sap of Ficus elastica was ever made into natural rubber, only to be replaced eventually by a different tree yielding a better product. Many ficuses adjust well to the lower levels of humidity in our homes, especially in winter, when central heating keeps our indoor humidity levels at their lowest. In fact, they actually transpire considerable amounts of water into the air, increasing the humidity levels in our homes. This definitely gives them an edge here in Colorado! Most tropical ficuses grow well at temperatures of around 65 to 80 F, temperatures within the range of most interiors. Another advantage is that they don’t usually require special care, and even people with a casual approach to indoor greenery can keep them alive for extended periods. You can still kill them, of course, but you have to be either fairly negligent or overly generous with the watering can. The ficus most commonly seen in the home is the graceful, tree-like weeping fig, Ficus benjamina, which is now available with attractive variegated foliage. In contrast to most houseplants, these fast growing plants are desirable because they allow themselves to be pruned into beautiful tree shapes. Although they would prefer higher levels of light, plant quality can be maintained at 150-250 foot candles. Ficus maclellandi, another attractive tree-like ficus with a triangular canopy, has narrow leaves about 8-10” long. It was imported from Thailand into Hawaii in the early 1980’s and later marketed by Kraft Gardens, Inc. and Aloha Foliage. The Kraft Gardens name was banana-leaf fig, an unfortunate choice, since the plant isn’t even remotely suggestive of a banana. Ficus alii, the Aloha Foliage name, on the other hand seems to have stuck. (Alii is the Hawaiian word for royalty.) The plant is extremely fast growing and quite durable. I have to keep pruning mine back! It’s exceptionally tolerant of dryness and like the rubber tree, it will survive in reduced light (about 200 foot candles) for extended periods. Naturally, it does better at higher light levels of 4,000-6,000 foot candles. The fiddle-leaf fig, Ficus lyrata gets the prize for interesting, large foliage. As its name implies, the leaves are shaped like a fiddle and are rough and leathery in texture. They reportedly get as large as 18” long and a foot wide, however it’s unlikely that you’ll ever see that size on a potted plant. For a time in Honolulu, I had several trees planted in my garden, and the leaves never approached that size. Again, as with the weeping fig and ficus alii, an adequate maintenance level of light is about 250 foot candles, though for growth the plant prefers 2,000 to 6,000 foot candles. Unlike ficus alii, this plant is not at all drought tolerant. You’ll need to water regularly, but not to excess. The creeping fig or Ficus pumila performs well at fairly bright light, but can adapt to lower levels of light. Unfortunately, it needs a relatively humid environment. Here in Colorado it’s a good terrarium plant. If the humidity in your home is moderately high, you can use it as a groundcover for large plants. A variegated cultivar with leaves edged in white is now available. In tropical areas, this plant often climbs up walls of buildings and stone barriers of all types to great heights. The residents of a well-known high-rise condominium building in Honolulu had a topping off party when the creeping fig reached the roof! There are several worthy new introductions to our ficus repertoire. Ficus aspera, the clown fig, is a fairly recent arrival on the scene. An attractive plant with striking, variegated green and white foliage, it has a fruit with a reddish cast, resembling a clown’s nose. Hence the name, clown fig. It’s prone to spider mites, but its interesting foliage and fruit still make it worth growing. The blue fig, or ficus petiolaris is another attractive newcomer. It has heart-shaped, whorled leaves with pronounced pink veination in good light and a swollen stem or caudex for water storage. Another plant, sold as the Congo fig (Dorstenia elata) is different enough to be placed into another genus, but still in the fig family (Moraceae). It is an understatement to say that it its eight-inch leaves are shiny. They look as though someone emptied a can of leaf-shine on them! It also has an unusual flat fruit, occasionally producing viable seeds. A new dwarf edible black fig, Ficus carica ‘Petite Negra’ can grow from 5 to 8 feet when planted out in milder climates. Container grown here in Colorado in an indoor/outdoor setting, it should remain much smaller. It’s supposed to produce two crops a season, one in late July and one in September. Since figs are self fertile, fruiting should not be a problem, even in an indoor setting, provided it receives enough light. Stay tuned! Watering ficuses can be tricky, especially if the plants are large. Allow the soil in large pots to dry out to a depth of 2-3 inches in between waterings. Plants in lower light will need much less water. If you forget and let them get too dry, ficuses will may suddenly drop all their leaves, but unless they are totally parched you can bring them around with regular watering. No fertilizer at this point, please! Check to see if the branches are still supple. If so, the plant can be saved. Leaf drop may also occur as a result of sudden changes of temperature and overwatering. The common insect pests found on houseplants also attack ficuses. Infestations of scale insects, mealy bugs, and spider mites are not atypical. It’s always a challenge dealing with these pests, especially when the plants are large. Horticultural oils mixed with water are especially effective for dealing with scale insects, but will also work on the other two pests. It’s best to do this outside during warm weather, but never in direct sun to avoid damage to the leaves. Indoors, the logistics of shielding your walls, furniture and floor coverings from damage can prove formidable. You’ll generally need to apply the oil-water mixture more than once. Ficuses are usually not damaged by this treatment, unless you get carried away and add too much of the oil. Remember, your goal is to suffocate the insects, not the plant! In the winter months, cotton wipes or Q-tips dipped in alcohol can control scale and mealy bugs, especially if the infestation is not too severe. Spider mites are averse to water and are fairly easy to control with vigorous showering. Low-impact, pyrethrin-containing sprays also kill spider mites and mealy bugs. You get an extra bonus for growing ficuses in your home! Apart from their attractiveness and ability to thrive indoors, they are constantly at work cleaning the air you breathe. Both the rubber plant and the weeping fig excel at removing gaseous formaldehyde, a common indoor pollutant given off by textiles, adhesives, carpeting, paints, particle board, wall coverings and a host of other products commonly used in the home. Additionally, the weeping fig also removes the solvents xylene and toluene, as well as ammonia. Overall though, the rubber plant and ficus alii get somewhat higher marks for removing more pollutants. So, why not green up your home and reap the benefits? ----------- Sources: Appell, S.D., ed. Landscaping Indoors: Bringing the Garden Inside. New York: Brooklyn Botanical Garden, 2000. Blessington, T.M. and P.C. Collins. Foliage Plants: Prolonging Quality — Postproduction, Care & Handling. Batavia, IL: Ball Publishing, 1993. Hamilton, P. The ABC’s of Indoor Ficus Trees. Pacific Grove, CA: New Leaf Press, 1991. (DBG Library) McColum, S. and T. Risley. Plant Basics: A Manual for the Care of Indoor Plants. 1994. (Available from Garden Tapestry, Inc., 719 W. McGraw, Seattle, WA 98119, (206) 213-0162) $9.50. Martin, T. Once upon a Windowsill: A History of Indoor Plants. Portland, OR: Timber Press, 1988. (DBG Library) Wolverton, B.C. How to Grow Fresh Air. New York: Penguin Books, 1996. (Editor’s note: No doubt the Web is huge – a search on Ficus Alii produced almost 700 results, including many artificial plants and trees. One source would like you to know that their 8’ tree has 1,539 leaves!) At http://content.honeywell.com/yourhome/eiac-air_cleaners/plants.htm I find the following list of “air-cleaning” plants, including two ficuses mentioned above (originally from a now-defunct Website, www.HealthEOffice.com):

Ficuses: the Workhorses of the Interior Landscape

by Paula Szilard

Since the latter part of the nineteenth century, few plants have put in a more frequent appearance in our homes and offices than members of the genus Ficus. There are over 800 species in this genus, which includes the weeping fig (Ficus benjamina), the banyan tree (Ficus benghalensis), the Bo tree (Ficus religiosa), the rubber tree (Ficus elastica) and the common edible fig (Ficus carica). Members of this genus are often used in our interior landscaping because they can be pruned easily into tree-like shapes and add height and structure to our indoor plantings. In nature, though, they are sometimes stranglers, starting out as epiphytes on branches or crotches of trees, but eventually growing so large that they strangle their host.

Ficuses have remained popular since they were introduced in Victorian times because they have many attributes which make them suitable for indoor culture. Though most grow under high light conditions in nature (often full sun), they adapt well to the reduced light levels available in our homes. The rubber tree, Ficus elastica, can be sustained for long periods on about 250 foot candles, although about 4,000 to 8000 foot candles are desirable for good growth. (As a point of reference, on the dreariest, most overcast winter day in Colorado, a measurement taken at the glass of an east or west window is roughly 300 f.c. and the measurement on a sunny winter morning at an east window is over 5000 f.c.)

Still popular, though losing ground to its more attractive cousins, the rubber plant was a favorite in the Victorian home. Though all ficus species release a type of milky latex when wounded, only the sap of Ficus elastica was ever made into natural rubber, only to be replaced eventually by a different tree yielding a better product.

Many ficuses adjust well to the lower levels of humidity in our homes, especially in winter, when central heating keeps our indoor humidity levels at their lowest. In fact, they actually transpire considerable amounts of water into the air, increasing the humidity levels in our homes. This definitely gives them an edge here in Colorado! Most tropical ficuses grow well at temperatures of around 65 to 80 F, temperatures within the range of most interiors. Another advantage is that they don’t usually require special care, and even people with a casual approach to indoor greenery can keep them alive for extended periods. You can still kill them, of course, but you have to be either fairly negligent or overly generous with the watering can.

The ficus most commonly seen in the home is the graceful, tree-like weeping fig, Ficus benjamina, which is now available with attractive variegated foliage. In contrast to most houseplants, these fast growing plants are desirable because they allow themselves to be pruned into beautiful tree shapes. Although they would prefer higher levels of light, plant quality can be maintained at 150-250 foot candles.

Ficus maclellandi, another attractive tree-like ficus with a triangular canopy, has narrow leaves about 8-10” long. It was imported from Thailand into Hawaii in the early 1980’s and later marketed by Kraft Gardens, Inc. and Aloha Foliage. The Kraft Gardens name was banana-leaf fig, an unfortunate choice, since the plant isn’t even remotely suggestive of a banana. Ficus alii, the Aloha Foliage name, on the other hand seems to have stuck. (Alii is the Hawaiian word for royalty.) The plant is extremely fast growing and quite durable. I have to keep pruning mine back! It’s exceptionally tolerant of dryness and like the rubber tree, it will survive in reduced light (about 200 foot candles) for extended periods. Naturally, it does better at higher light levels of 4,000-6,000 foot candles.

The fiddle-leaf fig, Ficus lyrata gets the prize for interesting, large foliage. As its name implies, the leaves are shaped like a fiddle and are rough and leathery in texture. They reportedly get as large as 18” long and a foot wide, however it’s unlikely that you’ll ever see that size on a potted plant. For a time in Honolulu, I had several trees planted in my garden, and the leaves never approached that size. Again, as with the weeping fig and ficus alii, an adequate maintenance level of light is about 250 foot candles, though for growth the plant prefers 2,000 to 6,000 foot candles. Unlike ficus alii, this plant is not at all drought tolerant. You’ll need to water regularly, but not to excess.

The creeping fig or Ficus pumila performs well at fairly bright light, but can adapt to lower levels of light. Unfortunately, it needs a relatively humid environment. Here in Colorado it’s a good terrarium plant. If the humidity in your home is moderately high, you can use it as a groundcover for large plants. A variegated cultivar with leaves edged in white is now available. In tropical areas, this plant often climbs up walls of buildings and stone barriers of all types to great heights. The residents of a well-known high-rise condominium building in Honolulu had a topping off party when the creeping fig reached the roof!

There are several worthy new introductions to our ficus repertoire. Ficus aspera, the clown fig, is a fairly recent arrival on the scene. An attractive plant with striking, variegated green and white foliage, it has a fruit with a reddish cast, resembling a clown’s nose. Hence the name, clown fig. It’s prone to spider mites, but its interesting foliage and fruit still make it worth growing.

The blue fig, or ficus petiolaris is another attractive newcomer. It has heart-shaped, whorled leaves with pronounced pink veination in good light and a swollen stem or caudex for water storage. Another plant, sold as the Congo fig (Dorstenia elata) is different enough to be placed into another genus, but still in the fig family (Moraceae). It is an understatement to say that it its eight-inch leaves are shiny. They look as though someone emptied a can of leaf-shine on them! It also has an unusual flat fruit, occasionally producing viable seeds.

A new dwarf edible black fig, Ficus carica ‘Petite Negra’ can grow from 5 to 8 feet when planted out in milder climates. Container grown here in Colorado in an indoor/outdoor setting, it should remain much smaller. It’s supposed to produce two crops a season, one in late July and one in September. Since figs are self fertile, fruiting should not be a problem, even in an indoor setting, provided it receives enough light. Stay tuned!

Watering ficuses can be tricky, especially if the plants are large. Allow the soil in large pots to dry out to a depth of 2-3 inches in between waterings. Plants in lower light will need much less water. If you forget and let them get too dry, ficuses will may suddenly drop all their leaves, but unless they are totally parched you can bring them around with regular watering. No fertilizer at this point, please! Check to see if the branches are still supple. If so, the plant can be saved. Leaf drop may also occur as a result of sudden changes of temperature and overwatering.

The common insect pests found on houseplants also attack ficuses. Infestations of scale insects, mealy bugs, and spider mites are not atypical. It’s always a challenge dealing with these pests, especially when the plants are large. Horticultural oils mixed with water are especially effective for dealing with scale insects, but will also work on the other two pests. It’s best to do this outside during warm weather, but never in direct sun to avoid damage to the leaves. Indoors, the logistics of shielding your walls, furniture and floor coverings from damage can prove formidable. You’ll generally need to apply the oil-water mixture more than once. Ficuses are usually not damaged by this treatment, unless you get carried away and add too much of the oil. Remember, your goal is to suffocate the insects, not the plant! In the winter months, cotton wipes or Q-tips dipped in alcohol can control scale and mealy bugs, especially if the infestation is not too severe. Spider mites are averse to water and are fairly easy to control with vigorous showering. Low-impact, pyrethrin-containing sprays also kill spider mites and mealy bugs.

You get an extra bonus for growing ficuses in your home! Apart from their attractiveness and ability to thrive indoors, they are constantly at work cleaning the air you breathe. Both the rubber plant and the weeping fig excel at removing gaseous formaldehyde, a common indoor pollutant given off by textiles, adhesives, carpeting, paints, particle board, wall coverings and a host of other products commonly used in the home. Additionally, the weeping fig also removes the solvents xylene and toluene, as well as ammonia. Overall though, the rubber plant and ficus alii get somewhat higher marks for removing more pollutants. So, why not green up your home and reap the benefits?

-----------

Sources:

Appell, S.D., ed. Landscaping Indoors: Bringing the Garden Inside. New York: Brooklyn Botanical Garden, 2000.

Blessington, T.M. and P.C. Collins. Foliage Plants: Prolonging Quality — Postproduction, Care & Handling. Batavia, IL: Ball Publishing, 1993.

Hamilton, P. The ABC’s of Indoor Ficus Trees. Pacific Grove, CA: New Leaf Press, 1991. (DBG Library)

McColum, S. and T. Risley. Plant Basics: A Manual for the Care of Indoor Plants. 1994. (Available from Garden Tapestry, Inc., 719 W. McGraw, Seattle, WA 98119, (206) 213-0162) $9.50.

Martin, T. Once upon a Windowsill: A History of Indoor Plants. Portland, OR: Timber Press, 1988. (DBG Library)

Wolverton, B.C. How to Grow Fresh Air. New York: Penguin Books, 1996.

(Editor’s note: No doubt the Web is huge – a search on Ficus Alii produced almost 700 results, including many artificial plants and trees. One source would like you to know that their 8’ tree has 1,539 leaves!)

At http://content.honeywell.com/yourhome/eiac-air_cleaners/plants.htm I find the following list of “air-cleaning” plants, including two ficuses mentioned above (originally from a now-defunct Website, www.HealthEOffice.com):