Indoor bonsai hobbyists often create total mini-environments in their homes. Some, in very cold climates, keep their tropical and sub-tropical species inside all year.
Others move their bonsai outdoors in spring and back in again come fall.
By following some basic care instructions for indoor bonsai, many of these plants not only survive, but thrive in their artificial environments!
The basics for growing bonsai trees indoors are not much different than those of house plants indoors. Can’t grow houseplants?
Check out Houseplant Care Tips for more advice.
Things to Remember: The larger the plant the more light it needs; over-watering can be a problem and keep an ever vigilant eye for pests.
As beautiful as all of these treasures can be, there is no magic that allows any of them to grow in the dark. For some growers, a window with a bright exposure is sufficient. Artificial light such as grow lights and fluorescent tubes are frequently used.
No mention of growing bonsai under fluorescent lights is complete without mentioning Jack Wikle!
Jack is growing bonsai trees indoors under 4 ft long 40 watt, two tube, cool white fluorescent fixtures, 16 hrs a day. No, not special ‘grow lights’.
An economical timer turns the lights on and off automatically.This photo shows an example of the basics used by Jack Wikle:
Metal Halide Lamps
“a member of the high-intensity discharge (HID) family of lamps, produce high light output for their size, making them a compact, powerful, and efficient light source …
Originally created in the late 1960s for industrial use, metal halide lamps are now available in numerous sizes and configurations for commercial and residential applications … metal halide lamps operate under high pressure and temperature, and require special fixtures to operate safely”.
Jack is also the only person I know growing bonsai trees, who has managed to keep two junipers as indoor plants under lights for twenty years!
Yes, I’ve seen them!
(However, junipers are not recommended indoors for the novice or faint of heart.)
Check out Jack’s article to see the details of his amazing light and stand set-ups for Growing Bonsai Trees Under Lights.
In addition to fluorescents, large bonsai especially, may require more powerful (and more expensive) metal halide lamps.
Not only do they have great intense light, they exude a certain amount of heat that tropicals will love.
Bonsai hobbyists growing bonsai trees under metal halide swear by them!
Most homes do not have enough humidity in winter to support tropical plants. Air blown heat (especially) depletes the necessary humidity.
Growing bonsai trees indoors will enjoy some humidity. However, misting does very little if anything to create humidity in a room. Humidifiers are much better and easier. They are often used by many indoor plant people.
If you think a humidity tray will help create humidity, I disagree. (Although I do recommend them for another reason.)
Please see the section on the Bonsai Myths page to read about the Humidity Tray Myth
Instructions such as water “every day” or “once a week” are not reliable. Be sure you have explicit instructions and see the watering bonsai page.
Find out if your plant likes to be “evenly moist”, “wet” or “a little dry between waterings.” In winter, never use ice cold water directly from the tap!
Temperature and Air
Even the large old banyan trees of South Florida drop leaves in nature when the temperatures fall below 50oF. They know it’s cold! Tropical bonsai like to be warm. Be cautious indoors about cold windowsills and drafts.
Although cold drafts and direct hits from air conditioning can be harmful, air movement is necessary to keep down the plant pest population. In most cases, an oscillating fan works just fine for growing bonsai trees indoors.