Updated: Jan 7
We have all heard it before, Somebody new to Bonsai purchases their very first tree and they are so in aww of it that they want to keep it indoors so they can gaze at its beauty all day long. Soon after the new Bonsai Hobbyist will take to the internet to share photos of their new found love and seek advice from more experienced enthusiast's.
This is usually the part where they share a photo of the tree on a windowsill, kitchen bench or bed side table and get hit with a barrage of " Get it outside " - " Bonsai don't live indoors" - " Insert unsupportive rambling here ".
We all have to start somewhere and even i put my very first Juniper on my bedside table before doing some research and finding out quickly that is the last place it should be.
So here is a brief description of why Bonsai shouldn't be kept inside with some helpful information.
Air movement is needed to help move moisture from the tree, if you keep a tree in doors and keep the foliage moist you can end up with fungal infections that will do more harm then good for your tree.
Keeping a tree out doors in the wind will move water through the tree quicker through transpiration helping the tree to move nutrients and other important elements needed for the trees growth, this will also mean you will need to water the tree more regularly to keep the trees moisture levels in check.
Temperature / Season Cycles-
Season cycles play an important role in Bonsai and plant life in general, this is broken up into 2 main aspects
1. Sunlight ( which we will talk about next )
Once the weather begins to warm the trees are able to safely push buds and new softer growth without the risk of frost impacting the new growth, the tree is also able to move more resources through transpiration due to the warmer weather meaning the tree can take up nutrients to support new growth and health. Once the weather begins to cool through autumn the trees begin to wrap up their growing cycle and prepare for rest through winter which we call dormancy. With out this rest the trees can be greatly impacted.
If a tree is kept indoors the temperature is usually controlled to suit human comfort, its cool through summer and warm through winter. This will confuse the tree and throw off its natural cycle.
For a tree to go through its proper cycle it reads the intensity and length of daylight. As the days get longer and warmer from spring through till summer the tree enters its growing period. The tree now knows it is safe from harmful frost and can push the new buds and growth, once this new growth hardens off it has the most amount of day light to be able to photosynthesize and restore energy.
Once the days begin to become shorter from autumn through till winter the tree prepares for hibernation or dormancy by storing its energy and dropping its leaves if it is deciduous, all trees need this rest period through winter otherwise the tree will eventually become weaker and weaker until it dies.
If a tree is kept inside under a grow light, on a table or near a window it can not read the cycle it should be in.
When a Bonsai Tree is kept in doors you can not water the tree properly as needed unless you want to make an awful mess of your windowsill or bedside table. To water a tree properly in simple terms we need to make sure we wet the entire root ball which can mean soaking the surface entirely 2 or 3 times. We water until we see a solid flow of water running from the drainage holes under neath.
Not only does this provide enough water for the tree but the action of water being pulled through the bonsai soil also feeds the tree with fresh oxygen and we know that a healthy tree is made up of a balance of water and oxygen.
On a lighter note if you don’t have access to rain water catchment it is good for your tree to get a dose of un treated clean rain water. This is not a major issue but being able to have your tree watered a good portion of the time by fresh water is helpful.
Obviously Bonsai can be indoors for a few days for shows / exhibition, to be put on display for a dinner party or even to be protected from harsh weather such as strong wind, hail or intense rain. People usually bring their trees indoors or into a studio for photos as it is easier to see details on a tree with a flat background rather then other tree or grass in the background which make finer branching and detail hard to see.
I hope this helps you understand a little bit more about why Trees need to be kept outside rather then indoors.
Enjoy your Bonsai Journey.