Indoor bonsai - AbsoluteAstronomy.com

Indoor bonsai are bonsai

Bonsai

is a Japanese art form using miniature trees grown in containers. Similar practices exist in other cultures, including the Chinese tradition of penjing from which the art originated, and the miniature living landscapes of Vietnamese hòn non bộ...

which are cultivated for the indoor environment. Traditionally, bonsai are temperate

Temperate

In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

climate trees grown outdoors in containers. Kept in the artificial environment of a home, these trees weaken and die. But a number of tropical and sub-tropical tree species will survive and grow indoors. Some of these are suited to bonsai aesthetics and can be shaped much as traditional outdoor bonsai are.

Note that bonsai

Bonsai

and similar practices like penjing
Penjing
Penjing , also known as penzai , tray landscape, potted scenery, potted landscape, and miniature trees and rockery is the ancient Chinese art of growing trees and plants, kept small by skilled pruning and formed to create an aesthetic shape and the complex illusion of age...

, hòn non bộ

Hòn Non Bô

Hòn Non Bô is the Vietnamese art of making miniature landscapes, imitating the scenery of the islands, mountains and surrounding environment as found in nature...

, and saikei
Saikei
literally translates as "planted landscape". It is the art of creating tray landscapes that combine miniature living trees with soil, rocks, water, and related vegetation in a single tray or similar container...

all involve the long-term cultivation of small trees in containers. The term bonsai is generally used in English as an umbrella term for all miniature trees in containers or pots. In this article bonsai should be understood to include any container-grown tree that is raised indoors and regularly styled or shaped, not just one being maintained in the Japanese bonsai tradition.

Indoor vs. traditional bonsai

The largest difference between indoor and traditional bonsai is, of course, the enjoyment of an attractive, fully leaved plant in winter instead of a dormant, leafless tree. Other differences include the faster growth rate of tropical plants, which accelerate all steps of the bonsai evolution. Moss

Moss

Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...

covering, a common soil covering for outdoor bonsai, will not survive indoor conditions.

Bonsai vs. other forms of house plant

Compared to the usual potted house plant, bonsai are rooted in a much smaller amount of soil. Consequently, they require more frequent watering and feeding. This form is therefore best suited for drought-resistant species. Compared to usual house gardening, bonsais require a lot more pruning, both of branches and roots. This often requires a significant shift in attitude for house gardeners.

The spiritual benefits of bonsai cultivation, in Japanese bonsai no kokoro are available equally to classical and indoor bonsai gardeners.

Cultivation and care

Many of the techniques used to grow and shape outdoor bonsai apply equally to indoor bonsai. For example, shaping techniques like pruning, wiring, and grafting work much the same for both types of bonsai. But indoor bonsai also have some special requirements for cultivation and care.

Lighting

An indoor room comfortably lit for human use provides too little light for most species of tree to grow. Few species will thrive with less than 500 lux

Lux

The lux is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface...

available several hours per day. Successful indoor bonsai cultivation requires either selecting from the short list of low-light-tolerant trees, or providing additional lighting for the trees. Insufficient light may not kill some species outright, but will make their growth so slow that the bonsai shaping techniques cannot be used: the plant will not grow back after pruning or leaf trimming.

The simplest way to provide extra light is to place the bonsai close to an outside window. Care must be taken not to harm the plant either with cold air entering through the window, or with high radiated heat from direct exposure to the sun. More controllable light, and more flexibility in situating the bonsai, can be obtained using artificial lighting. Fluorescent lighting (preferably with bulbs radiating growth-friendly spectra

Grow light

A grow light or plant light is an artificial light source, generally an electric light, designed to stimulate plant growth by emitting an electromagnetic spectrum appropriate for photosynthesis. Grow lights are used in applications where there is either no naturally occurring light, or where...

) and light-emitting diode lighting

LED lamp

An LED lamp is a solid-state lamp that uses light-emitting diodes as the source of light. The LEDs involved may be conventional semiconductor light-emitting diodes, organic LEDs , or polymer light-emitting diodes devices, although PLED technologies are not currently commercially available.Since...

can give sufficient light to support a significant number of indoor bonsai species. These lights also have the advantage of blending with other indoor lighting, so that the plants can be grown in normal living quarters. For plants needing the highest amount of light, or for large numbers of bonsai being maintained indoors, a space dedicated to bonsai cultivation

Growroom

A growroom is a room of any size where plants are grown under controlled conditions. The reasons for utilizing a growroom are countless. Some seek to avoid the criminal repercussions of growing illicit cultivars, while others simply have no alternative to indoor growing. Plants can be grown with...

can support high-intensity lamps and optionally the special ventilation or cooling often needed for their use.

Temperature

Suitable temperatures for indoor bonsai extend from standard room temperature

Room temperature

-Comfort levels:The American Society of Heating, Refrigerating and Air-Conditioning Engineers has listings for suggested temperatures and air flow rates in different types of buildings and different environmental circumstances. For example, a single office in a building has an occupancy ratio per...

downward. The best temperature range for a tree is determined by its species and, less directly, by its normal range in the wild. Tropical trees are usually tolerant of room temperature year-round but cannot tolerate temperatures approaching freezing, as might occur near an open window in cold weather. Semi-tropical and Mediterranean-climate trees often grow better when temperatures drop well below room temperature during winter months. The lower temperature, combined with shorter periods of daylight, triggers an expected annual dormancy which many non-tropical species need in order to thrive. These non-tropical trees need a cool location in the winter, such as a cool window ledge or "cold room" area in the house. In addition to the need for seasonal temperature variation, many non-tropicals grow better when there is a distinct difference between day temperatures (warm) and night (cooler).

Humidity

Indoor conditions, particularly in homes outside the tropics, imply very low humidity. Both air conditioning and room heating reduce air humidity significantly. Some tree species, such as ficus sp. with their waxy leaves, are tolerant of low humidity. Many species, however, require additional humidification to survive indoors. As with lighting, some humidification solutions can be integrated into the regular living area and some require a dedicated space. Local humidity can be raised by locating the bonsai containers over a tray of water, or by placing them in a bed of dampened sand. For better effect, the bonsai can be placed in enclosures, such as terrariums

Vivarium

A vivarium is a usually enclosed area for keeping and raising animals or plants for observation or research...

, that are humidified from within. For the maximum humidity, a dedicated room with high-capacity evaporative or misting humidifiers can support the most sensitive bonsai.

Tropical

The creation of bonsai is limited only by the imagination and talent of the gardener, although some species are much more suitable than others. Members of the genus Ficus
Ficus
Ficus is a genus of about 850 species of woody trees, shrubs, vines, epiphytes, and hemiepiphyte in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending into the semi-warm temperate zone. The Common Fig Ficus is a genus of...

are among the most versatile, while many succulents can be grown in a similar fashion. Here is an incomplete list of the most popular species.

Ficus benjamina: The Weeping Fig is a popular indoor tree that lends itself to the classical, upright form. It is one of the few tropicals that are accepted as "true" bonsai. The miniature cultivars like 'Too Little' are also well suited for bonsai. It forms aerial roots and can be shaped as a banyan
Banyan
A banyan is a fig that starts its life as an epiphyte when its seeds germinate in the cracks and crevices on a host tree...

tree. Ficus are intolerant to branch down-pruning; one must start with a small tree and keep it small. They are sensitive to stress.
Ficus neriifolia
Ficus neriifolia
Ficus neriifolia is a fig. It is commonly used in horticulture as an indoor plant or in bonsai, where its narrow leaves are an attractive attribute....

: According to Jerry Meislik, "the most useful fig for bonsai is the willow leafed fig. The small leaf is in excellent scale for bonsai and the tree has good branch ramification, good basal rootage and excellent aerial root formation."
Schefflera arboricola
Schefflera arboricola
Schefflera arboricola is a flowering plant in the family Araliaceae, native to Taiwan. It also goes by the common name "Dwarf Umbrella Tree."-Growth:...

: The Hawaiian umbrella tree is a popular, hardy houseplant that is ideal for irregular, banyan or roots-on-rock forms. Since it can sprout on old wood, an old specimen can be pruned back to a stockier shape with thick trunk and roots. It tolerates root exposure very well, is drought-resistant and requires a moderate amount of light. Under high humidity conditions, it produces aerial root
Aerial root
Aerial roots are roots above the ground. They are almost always adventitious. They are found in diverse plant species, including epiphytes such as orchids, tropical coastal swamp trees such as mangroves, the resourceful banyan trees, the warm-temperate rainforest rātā and pōhutukawa Aerial roots...

s and can therefore be shaped as a banyan
Banyan
A banyan is a fig that starts its life as an epiphyte when its seeds germinate in the cracks and crevices on a host tree...

tree.
Crassula ovata: The jade plant is a very robust and drought-resistant house plant. The miniature cultivars like the baby jade plant (C. ovata arborescens) is considered the best plant for a first bonsai. This plant will sprout on old wood. Thus, an old specimen can be pruned back to a stockier shape with thick trunk. It is kept dry in winter, placed outdoors in summer for full growth. Its roots are thin and cannot be exposed.
Portulacaria afra
Portulacaria afra
Portulacaria afra, also known as Dwarf Jade Plant, Elephant's Food, Elephant Bush, and Spekboom in Afrikaans, is a small-leaved succulent found in South Africa.-Description:...

: The dwarf jade looks a lot like a baby jade plant and is used similarly.
Dracaena marginata: The dragon plant has an interesting palm-like shape. It can sprout on old wood. It does not tolerate root exposure.
Schlumbergera: the Christmas cactus does not have a real trunk but easily lends itself to a cascade-type bonsai shape. It tolerates shade, not drought.
Cycas revoluta
Cycas revoluta
Cycas revoluta , is a plant native to southern Japan. Though often known by the common name of king sago palm, or just sago palm, it is not a palm at all, but a cycad.-Description:...

: This plant is often used as an indoor bonsai. Though it does not have a traditional tree shape, it can give an image of a tropical island.
Tamarindus indica The tamarind has recently become popular in bonsai culture, frequently used in Asian countries like Indonesia, Taiwan and the Philippines. In the last Japan Airlines World Bonsai competition, Mr. Budi Sulistyo of Indonesia won the second prize with an ancient tamarind bonsai.

Small succulents may be used as accent plants:

Rhipsalis (Hatiora) salicornioides
Rhipsalis salicornioides
Rhipsalis salicornioides is originally a forest cactus, growing as epiphytes at elevations between 0 and 1850 meters in Brazil...

Other climatic origins

With proper care, a number of non-tropical plants can also thrive as indoor bonsai.

Araucaria heterophylla
Araucaria heterophylla
Araucaria heterophylla is a distinctive conifer, a member of the ancient and now disjointly distributed family Araucariaceae. As its vernacular name Norfolk Island Pine implies, the tree is endemic to Norfolk Island, a small island in the Pacific Ocean between Australia, New Zealand and New...

: The Norfolk Pine does well indoors, but is not easily shaped to bonsai styles.

Ardisia crenata: The spear-flower will flower and produce berry-like fruit when grown indoors.

Bougainvillea
Bougainvillea
Bougainvillea is a genus of flowering plants native to South America from Brazil west to Peru and south to southern Argentina . Different authors accept between four and 18 species in the genus...

: This flowering shrub, native to South America, will grow indoors with sufficient light.

Bucida
Bucida
Bucida is a genus of flowering plants in the Indian almond family, Combretaceae. It contains the following species :* Bucida angustifolia * Bucida buceras L...

molineti: The black olive is native to southern Florida in the USA, and has a compact growth habit suited to bonsai forms.

Boxwood
Buxus
Buxus is a genus of about 70 species in the family Buxaceae. Common names include box or boxwood ....

: Found on nearly every continent, boxwood varieties are tough but attractive bonsai.

Carmona microphylla
Carmona (plant)
Carmona is a genus of flowering plants in the borage family, Boraginaceae. Members of the genus are commonly known as Scorpionbush....

: The sturdy trunk and glossy green leaves of the Fukien Tea make an attractive indoor bonsai.

Cupressus macrocarpa
Cupressus macrocarpa
Cupressus macrocarpa, commonly known as Monterey Cypress or Macrocarpa, is a species of cypress that is endemic to the Central Coast of California. In the wild, the species is confined to two small populations, near Monterey and Carmel, California. These two small populations represent what was...

: The Monterrey Cypress is one of the few evergreen conifers that can be grown indoors.

Ligustrum
Ligustrum
Ligustrum is a genus of about forty species of erect, deciduous or evergreen shrubs, sometimes forming small or medium-sized trees. They are now all known by the common name of privet.-Selected species:...

sp.: Some privet species, including Ligustrum japonica and Ligustrum rotundifolium, are suitable subjects for indoor bonsai.

Serissa
Serissa
Serissa is a genus of flowering plants in the family Rubiaceae, containing only one species, Serissa foetida. It is native to open sub-tropical woodlands and wet meadows in southeast Asia, from India, and China to Japan...

: This is a delicate flowering plant with tiny leaves that can grow indoors year round.

Ulmus parvifolia
Ulmus parvifolia
Ulmus parvifolia, commonly known as the Chinese Elm or Lacebark Elm, is a species native to China, Japan, North Korea and Vietnam...

: The Chinese elm is often used as outdoor bonsai, and it can be raised indoors as well.