By nature of trees they are meant to be outdoor.Maple are cold hardy tree, and they will thrive in ideal condition. Who best then mother nature for creating ideal climate. Maple will grow in cold climate because they need a period of cold to rest and rejuvenate. This apply to all tree's, hence bonsai, that grow in cold climate. Growing a tree indoor will lack natural elements. One, it will lack light, wich is essential to growth. It will lack humidity, wich will cause leaves to dry faster. Leaves are in constant transpiration, and humidity help the process. One thing, is that indoor, you most likely keep your temeprature to at least 20c in winter. Colder climate tree that need a period of rest after they loose their leaves, will require a maximum of 5c to go dormant and rejuvenate.Now, their must be a type of tree that dont need sleep in winter? Yes there is. What you must ask yourself, is what climate conditions can I offer to a future tree?Well, you can start by having a constant temperature in the house, maybe hotter in the summer. Reducing lighting and maybe humidity by misting my tree once or twice a day.So with these condition on hand, what type of tree can live with these conditions?Surely a tropical tree would liked to be in hot temperature all day.That is why Tropical types of trees do well indoor.I have a few tropical tree's, and keep them indoor in winter but I always bring them outside in late spring. Their growth rate is 10 times faster outside because it has lots of suns, humidity and hot temperature.Indoor, the tree survive, but is a really slow grower.
Avid full time hobby bonsai grower. As been practicing bonsai and gardening for more then 8 years. Owner of http://www.mishobonsai.com, a website with ressource for bonsai seeds and tree seeds.
