Why you cannot keep bonsai trees indoors

[Bonsai Nut]

Probably the biggest misunderstanding people have when starting out in bonsai - and the greatest mistake they make - is to think that they can keep bonsai trees indoors. With only a few exceptions, all bonsai trees must be kept outside, or they will die a quick and certain death. Even the short list of tropical trees that can be kept indoors would do better if they were kept outside. I wanted to create a thread for people to discuss this subject - and the horticultural reasons why this is true - so that we can avoid unnecessary tree deaths and the disappointment bonsai beginners feel when their first efforts end in failure.

Sadly, I have found that some retailers even sell their bonsai trees like they were houseplants - or label them as "indoor bonsai" to differentiate them from "outdoor bonsai". There is no such differentiation. They are all outdoor bonsai... though a tiny percentage may be kept alive indoors if the proper environment can be provided. This is certainly the exception and not the rule.

Worst yet is people who post on social media fake information like "I kept my bald cypress indoors and it did fine!". This thread is here to debunk that nonsense.

I will be editing this post as I have time - to create a lasting resource here on the site.

 

[Hartinez]

Probably the biggest misunderstanding people have when starting out in bonsai - and the greatest mistake they make - is to think that they can keep bonsai trees indoors. With only a few exceptions, all bonsai trees must be kept outside, or they will die a quick and certain death. Even the short list of tropical trees that can be kept indoors would do better if they were kept outside. I wanted to create a thread for people to discuss this subject - and the horticultural reasons why this is true - so that we can avoid unnecessary tree deaths and the disappointment bonsai beginners feel when their first efforts end in failure.

Sadly, I have found that some retailers even sell their bonsai trees like they were houseplants - or label them as "indoor bonsai" to differentiate them from "outdoor bonsai". There is no such differentiation. They are all outdoor bonsai... though a tiny percentage may be kept alive indoors if the proper environment can be provided. This is certainly the exception and not the rule.

Worst yet, is people who post on social media fake information like "I kept my bald cypress indoors and it did fine!". This thread is here to debunk that nonsense.

I will be editing this post as I have time - to create a lasting resource here on the site.

Great thread idea. The only local nursery that sell bonsai have them all in a green house year round. Mostly Procumbens for that matter and none of them ever look truly healthy. It’s a bummer that when people ask me where they should buy a tree and I have to recommend they order from a reputable bonsai dealer and not the local business.

 

[Gabler]

To be fair, if you invest in an expensive setup (which is impractical for newbies) you can successfully grow trees indoors. There's a member of Brandywine Bonsai who breeds reptiles for a living. He keeps his tropical trees in his basement, which has an ambient temperature above 80°F and a relative humidity of about 80%. The trees grow under UVB lamps intended to replicate sunlight, so the reptiles can synthesize enough vitamin D. The trees grow better indoors under those conditions than they do outdoors.

 

[BrianBay9]

Well lets start with light. Do you ever have to wear sunglasses in your living room? The only places where I've seen somewhat successful indoor growing are spaces designed for it, and I needed sunglasses to work in them. Light intensity and the spectrum available to trees are found outside, not in. Your can somewhat replicate that with a bunch of effort and money but you'll create a space you can't comfortably live in.

 

[Gabler]

Well lets start with light. Do you ever have to wear sunglasses in your living room? The only places where I've seen somewhat successful indoor growing are spaces designed for it, and I needed sunglasses to work in them. Light intensity and the spectrum available to trees are found outside, not in. Your can somewhat replicate that with a bunch of effort and money but you'll create a space you can't comfortably live in.

I guess next would be either humidity or airflow. Indoor air is dry and stale.

 

[Bonsai Turtle]

... The only local nursery that sell bonsai have them all in a green house year round. Mostly Procumbens for that matter and none of them ever look truly healthy. ...

Those might not be healthy due to a variety of reasons but greenhouse growing isn't even close to "indoor" conditions.

 

[Hartinez]

Those might not be healthy due to a variety of reasons but greenhouse growing isn't even close to "indoor" conditions.

Obviously it’s not the same. It’s probably why they are not dead. but keeping a juniper in a giant greenhouse year round, that has a highly regulated year round temperature, in potting soil, is certainly why they do not look great, or at the very least the reason they are susceptible to what ever is ailing them. It also doesn’t help when the signage in the very same greenhouse next to the very same trees, suggests indoor growing. So yeah, I will not be recommending my local nursery as a place to purchase quality bonsai trees.

 

[Canada Bonsai]

Thank you for starting this thread.

This is one the biggest challenges for me. As you mention, there are indeed many shops in North America that have an 'indoor bonsai' section in their store and/or on their website.

Every year leading up the holidays and valentines day I receive a higher volumes of emails than usual from people seeking to offer bonsai as gifts -- they ask for my help choosing one. I am always careful to specify in my responses, in one way or another, that the trees need to be kept outdoors and require protection in winter.

I remember having conversations with my mentor and close friends who have helped me shape this company about what strategies I could take to 'avoid' this audience altogether. One strategy has been species selection: I do not sell a single plant that could potentially be kept indoors despite the fact that I do have a strain of Chinese Elm here that has been kept indoors successfully for 30 years by my colleagues. I did this because I wanted to be able to say that 100% of the trees I sell are outdoor trees, without exception. Another strategy I have taken is that I have chosen to sell fairly rough and/or young material in grow pots. I did this on the assumption that putting a young tree with some movement in a bonsai pot (see attached example) would make it appealing to the segment of the market that I did not want to be attracting. For the most part, my material comes bare root or in plastic pots and therefore attracts people who are more hands-on and presumably more researched. I always told myself that if I ever started producing batches of trees for mass markets (e.g. Birthdays presents, Valentines Day, Father/Mother's Day, etc.) either through website sales or stand sales at markets or garden centres I would only do so when I was equipped and qualified to accompany every sale with a take-home pamphlet and adequate education that was clearly display upfront prior to purchase. I started the company in 2018, and still have never got around to doing this because it is a lot of work to do well.

Despite all of this, I received an email yesterday from somebody who spent $4,500CAD on my store in the past 2 years asking me "Do you know why the leaves on my japanese maple are falling off?" Did this person really buy 30-35 pieces of rough stock from me--nothing that 'looked' like a bonsai--and not know what a deciduous tree does in fall? The point I'm making is, there's a limit to the ways I can prevent people from shopping my on website, and I lose sleep thinking about how many trees from me have been kept indoors and died, potentially very nice material sold to somebody with more budget than brains.

Looking forward to reading people's responses, hopefully to gain some ideas about to improve this situation.

 

[Gabler]

prevent people from shopping my on website

Why would you do that? As long as you are providing accurate information to your customers, it does not reflect poorly on you that they're killing trees. You have done nothing wrong.

 

[ShimpakuBonsai]

I could take to 'avoid' this audience altogether.

I don't think this would be a bad idea, just cater the audience you aim for.

Why would you do that? As long as you are providing accurate information to your customers, it does not reflect poorly on you that they're killing trees. You have done nothing wrong.

You can provide all the info you want but do customers read all the info when buying trees online?
I don't think so based on all the very basic questions we get asked here every day by newbees (buy the tree first and then start asking questions when the tree is not healthy anymore....)
And in today's digital world a good reputation where you have worked hard for can be destroid by a few negative online reviews of those newbees.

 

[Paradox]

No light on earth can truly simulate sunlight

Window glass filters out certain wavelengths of light so is not a substitute for real sunlight.

Temperate trees need the yearly seasonal cycle of light and temperature for their natural biological rhythm. This can not be reliably simulated indoors.

Air Inside a closed up house is not the same as outside.

In summary: you can not replicate nature Inside a house

 

[Zac]

When I was younger I became interested in bonsai and was gifted juniper bonsai already potted up boxed with tools and care booklet. It stated it was a indoor tree. I followed all the care instructions and it died. This was before the internet was mainstream. It bugged me and kinda turned me off to bonsai. Years later I bought another one and same results I didn't know better. Then I bought one from a bonsai nursery at local fall fest. The instructions said it was a indoor tree and I followed them. Sadly yet another dead tree. Alot of years went buy before I bought anymore from local nursery. These were sold as pre bonsai and guy said keep outside till winter then bring indoors. Well we heated with a woodstove so they didn't make it through winter. I then had internet and some books so I researched and found out I was getting bad info before. Then I realized that there's alot of bad info online also. I finally found this forum. I now have trees that are still living and slowly being developed into bonsai. But I still see it everywhere trees being sold as indoor bonsai even from so called bonsai nurseries.
Thank you for this forum and thanks too all the wonderful people on here that share their knowledge and help and put up with us newbies.

 

[Bonsai Nut]

I remember when I had some family visitors over and they were admiring some of the trees in my garden. (This was when we were living in SoCal, but it was winter). They approached a large elm and asked "is it dead?"
I said "No it's an elm tree and though it is a little warmer here, it's still winter - and it drops leaves just like the elm trees in fall where you live. Come spring it will bud back out again".
They seemed really surprised that a tree in a pot would behave the same way as a tree outside of a pot, but it is not unusual.

 

[Yamabudoudanshi]

This is going to be controversial, but I follow a guy here in Japan that has been growing Shinpaku, JBP, Japanese maples, etc. indoors for a few years now. I don't know much about his setup, but I do know he uses led lights and fans. His trees are all nicer than mine and appear to be very healthy.

Maybe it's not as impossible as we once thought?

 

[snowman04]

If you create outdoors in an indoor setting, it proves they are NOT indoor trees!!! I went thru this like so many of us. Cost me several trees...

 

[Kievnstavick]

I think this could be a great resource that can be pinned and then cross-posted to help people help themselves.

I think some information in the initial post about why trees can't really be indoors (giving examples/sources rather then just stating it as fact) can help some people have an understanding.

Followed by how to care for trees that are brought indoors/grown indoors. The types of products and what to look for to help people make informed choices on their grow lights instead of picking up the $15 blurple light from Amazon that was actually just a bulb with film over the glass.

Now to add to the discussion:

I have grown tropical trees indoors as well as started temperate tree seeds indoors under grow lights for the last 3 years. Growing a tree inside is possible; however like another post mentioned, these are outdoor trees grown indoors.

As these trees growing indoors are ultimately in a controlled environment, their entire survival is squarely set in the person's shoulders to provide them an environment for them to grow in. Lacking one critical element could lead to a systematic collapse.

Another topic to approach would be the differences between surviving and thriving. Most of my tropicals tend to do better indoors mostly because I have better and more stable tempatures. Keep in mind this would be purely anecdotal as I have to keep a much closer eye on my trees while they are indoors. I wouldn't say they are thriving under growlights, bur they are certainly healthy and alive putting out pretty good growth once they adjust to the new indoor environment.

I have seen plenty of people on the internet show off this tree that have grown purely indoors for 2 years or so. With my basic understanding of horticulture, I place severe doubt in this examples as they could just be limping along rather then thriving. As for temperate trees, I'd rather see an example of one grown purely indoors for a several years to a decade before I really pay attention to those sorts of discussions. A couple years is not really a long enough time frame for a tree to show a decline in health unless it is a sapling.

 

[Michigan Tree Murderer]

Can't remember where, but I once read "Trees need the sun, & the seasons, and those are outside." Makes sense to me.

 

[coh]

This is going to be controversial, but I follow a guy here in Japan that has been growing Shinpaku, JBP, Japanese maples, etc. indoors for a few years now. I don't know much about his setup, but I do know he uses led lights and fans. His trees are all nicer than mine and appear to be very healthy.

Maybe it's not as impossible as we once thought?

It's definitely not impossible to grow some kinds of temperate trees indoors under artificial lighting. Here in the US, the best known practitioner is Jack Wikle, who has grown a number of species indoors all year under fluorescent lighting. I don't know the full list of species he's had success with, but I know it includes junipers, chinese elm, and I think cotoneaster and some type of small cypress...and possibly others. He has some information on line for anyone interested. He did a talk at our club a number of years ago and brought some of those trees. His junipers looked as healthy and vibrant as any I've seen, much better than mine which spend most of the year outdoors. One comment did stick with me from that presentation years ago. Jack was asked about the difficulties of growing indoors and he said "I'm glad that when I started this, I didn't know what I was trying to do was impossible."

 

[shohin_branches]

It's also important to understand that most big box "indoor bonsai" are super stressed out (if not dead already) and you're not getting a healthy tree. Most are grown in hot bright greenhouses all their lives then packed on a rack and thrown on a dark truck for a day or three then sit on the receiving bay for another day while they're casually inventoried and stocked with the same care as a box of screwdrivers. Drastic light decrease also means a sudden drop in water needs due to less photosynthesis. That peat perlite mix that was perfect in a hot bright greenhouse is now holding way too much moisture to be sitting 15 feet from fluorescent lights in a home depot for two weeks. So you're starting at a disadvantage. Get a healthy tree or shrub that's been sitting in the sun at a garden center. Most of the time they come with a one year warranty too!

 

[Emanon]

Probably the biggest misunderstanding people have when starting out in bonsai - and the greatest mistake they make - is to think that they can keep bonsai trees indoors. With only a few exceptions, all bonsai trees must be kept outside, or they will die a quick and certain death...

A definition of inside would be nice. There's a lot of speaking in generalities, which sometimes gets in the way of truly learning. I personally think it's less the fact that trees are inside and more the fact that trees need certain things to survive/thrive that most every instance of inside cannot provide. If you can provide those certain things inside, than you can keep all species of trees inside, as long as they are native to the area or otherwise climate appropriate. Defining or laying out exactly what those conditions are, might be of more benefit than a blanket rule (i.e. trees kept inside will not survive/thrive).

I'm thinking specifically of the time when I lived in a house with an open atrium. (It was Eichler home and if you search for that plus "open atrium" you can see examples of what I'm talking about. I attached a pictures of the type of atrium I'm talking about.) Even though I really wanted to move some of my bonsai trees into the atrium for aesthetic reasons, I never did. I avoided doing so because I had had the mantra drilled into my head over the years that there are no exceptions to the rule, or there is no inside set up, or version of inside, that will enable bonsai trees to survive/thrive. I didn't have a lot of outside space so I ended up forgoing buying more trees because of this rule. I could have, and would have, kept these trees in the atrium. Every time I proclaimed at my local bonsai meetings that I am the one guy that can successfully keep my bonsai trees inside, I'd get cut off before I could finish my sentence.

As I've gained more experience, I fully believe -- and again, I know most everyone really into bonsai will tell me I'm a fool -- that I could have kept my bonsai trees inside in the atrium because the space received unfiltered sunlight (at least 8-10 hours per day), and constant fresh air. I mean, hell, the trees not kept in pots thrived in this space, and in a couple of cases, they were the same exact species as my bonsai trees. Plus I could have not only kept my trees in the middle of the atrium, but if it was just a few, I could have moved them from one side of the atrium to the other as the sun moved throughout the day.