The problem with many tropical trees is that they need way more humidity than we have in normal livingroom conditions. They suffer as well, just for another reason.

What if the trees have humidity trays or a humidifier, would that be a close environment to outside? I have the trees in my bedroom upstairs right now. There is a window air conditioner upstairs at the end of the hallway, but I keep my bedroom door closed so my room is around 78°F most days, on hotter days it can get up to 82°F (I don't mind the heat I love summer). I just got a thermometer this year so I don't no how cold it will be in my room till winter. There are no vents upstairs, we just have a heater that plugs into the wall in the hallway upstairs so I am guessing my room will be around 65°F in the winter. I live in Minnesota so it gets pretty cold outside.

I really want the trees inside, so is there anything else I can do to mimic an outdoor environment? Or will I end up with unhealthy trees and wish I would have put them outside and listened to your advice?

Has anybody else had a tree as a houseplant and never brought it outside and had success?

Is it good for tropical trees to go dormant? If it is good, how cold does it have to be for them to go dormant?

Sorry if I ask too many questions. But I have a million more cause I am a complete beginner.😂

I am so thankful to all of you for helping me.😊 If this website did not exist I don't know what I would do.

Humidity can be measured. Do your own  research here. Test a humidity tray. Measure humidity around your trees, in the oposite part of the room and outdoors. Do it once a week until your heating system kicks in. Do your own conclusion.

I know minesota climate quite well. During the big starvation in Sweden more than 20% of the population moved to USA. The farmers from småland all ended up in minesota since the climate was basically the same. I could safely say we are in very similar climate.


Mimicing an outdoor environment pose different challenges depending on what climate you are looking for. The easiest climate to mimic indoors is humid tropical. That is by using a heatef terrarium with humidifier. But that is not really what we are doing in the bonsai hobby.

There are a lot of tropical decidious trees that need to go dormant yearly. But they are not commonly used in bonsai. At least not in temperate regions.

For a beginner the best start in the hobby is to grow locally hardy trees outdoors. Growing non hardy trees is just another hobby. You will always struggle to get a somewhat acceptable development speed and they will never be as good bonsais as the ones grown within their own hardiness zone.

I can with quite confidence say that the question about outdoors growing or indoor growing is the same question as if you will continue in the hobby or not. If you accept the fact that trees belong outdoors, you will likelly continue in the hobby. If you stubbornly hang on to the idea of growing trees indoors you will not.

OK, thank you.

I have 6 trees. So, maybe I could move half of them outside and leave the other 3 inside and see which trees turn out better. They are all tropical trees, so how do I protect them from the cold? Do I just bring them back inside with the other trees until it's warm again? 

Not all your trees is tropical. At least one is subtropical, the lemon tree.

I do not know what species your trees is so it is hard to give any good advice here. But in general:

Locally hardy trees: outdoors all year. In winter it is good to put them on the ground and let them be covered in snow.

Less hardy temperate trees: Outdoor all year but protected from frost in winter.

Subtropical trees: outdoors all year but protected from frost and above 5 degrees in winter.

Tropical trees: outdoors all year, but protected from frost and above 10 degrees in winter.

How to protect from frost: keep them in a cold room with suplemental light indoors in a room in your house that is heated to 0,5 or 10 degrees. Or isolate a greenhouse and heat it to the same temperatures with a heating fan and temperature controller.

This is why I always recomend locally hardy trees. For beginners. Most do not have an extra room to spare or a greenhouse.

And my most important general advice. When planning for any living creature, plant or animal. Do your research before getting them and not after. If you cannot provide the right care, just do not get them.

These are the trees I have:
Tropical trees: Albizia, Delonix Regia, Locust, Mimosifolia, and Jacaranda.
Subtropical: Lemon tree
Locally hardy: Spruce

This is what I read on the coldest temperatures these trees could handle before I got them:
Mimosifolia and Jacaranda 20°F-30°F
Delonix Regia 50°F
Albizia 22-20°F
Locust 10°F

Go do some more research your self. Robinia pseudoacacia (locust) is a temperate decidious tree from north america. Not at all tropical.

I got these trees from Amazon and the description said they were tropical trees. I did some research on the locust before I bought it, and it said to protect the tree from frost. Another website said it is recommended to move the honey locust bonsai outdoors during the warmer months, and bring it indoors only when the temperature drops below 50°F. So, I figured it was a tropical tree like the rest. It was a bonsai kit with 7 different trees and it was a good deal. Originally I was just going to get a Ficus, but the seeds all had bad reviews and cost the same price as the kit. The kit I got came with a ficus and a Wisteria but neither of them germinated. Since I am a beginner it was probably a bad idea to get so many but I could not help myself I love plants. So, it was hard to research on 7 different trees all at once. I did some more research on the locust today and it said that the tree needs to experience the seasons, but protected from frost. I don't have a green house or a spare room. So, what do I do?

The roots on my Delonix Regia are already poking through the bottom of the pot, is it still OK to leave it in that pot for a few years? 
Its hard to see the roots in the picture, because I poked them back inside the pot earlier.

Photosynthesis wrote: I don't have a green house or a spare room. So, what do I do?

What you are doing going forward is killing 7 small seedlings. But we will proboably never know. This forum have 100s of questions from beginners that bought those bonsai seed kits. Nobody has ever came back with a success story.

What you should do if you want to start with the hobby of bonsai is to get locally hardy trees at the age of 5-10 years from your closest garden center. This time of the year many of them start the autumn sale, emptying their stock for the winter with heavy discounts. If you are serious about bonsai, this is the perfect time to start building your colection. In spring 2026 you can start to train them as bonsai, just 1,5 years from now. Those seedlings will take 10 years or more before they are ready for any bonsai related work. If they survive first winter that is.

OK, I will see what trees I can find. If I can't find any, at least I have a spruce. I will let you know next spring if any of my tropical and subtropical seedlings are still alive.

So, just so I know for the spruce and future bonsais, if the roots poke through the bottom of a pot they were just put in, do I move them to a larger pot or poke the roots back in the pot.

Thank you for all of your help answering all of my questions.