First time poster, so I planted some bonsai trees from seeds and two of them are doing well and the others have died. Anyways the ones that did survive I’m worried will die during the winter. Should I bring them indoors? Put them in a small greenhouse inside or outside? I’m a little lost on what to do.

Hello and welcome to the empire.

First of all, you did not sow bonsai seeds, but normal tree seads. With the right care and styling it can become a bonsai tree in 20+ years. The first 10 years is just about growth and no styling. That is why most people here primary make bonsai from mature trees.

In order to anser your questions about your seadlings we need to know the species and your location and climate. Every species has its own hardiness and every climate is different. Sometimes when the tree hardiness and the climate dont fit some protection is needed. I keep some trees outside all year, some protected in greenhouse and some protected from frost (min 5c) in heated overwintering room. I never keep any trees in living room conditions.

Thank you, This website has really helped me so far. I have two rocky mountain pines and one Norway spruce. They are all about 3” big. I live in the north east United States so I experience all of the seasons. I’ll attach some photos.

Pictures of my trees

I dont know much about the temperatures in northeast USA. But Norway spruce is native to the very north of Sweden, Norway, Finland and Russia. It can handle temperature of -20 and below. Just put the pot on the ground, If you get snow, make sure the whole pot and tree is covered.

I have no experience with rocky Mountain pine. But a quick Google gives me a hunch it can be kept in the same way.

The pot you are using is good for now. If you want to create a bonsai in less than a life time it will need to be repotted to a huge pot or in the ground within a few years.