Typically, the "rule of thumb" is that anything that will grow outdoors in a temperate climate - like Euonymus japonicus - is not suitable to be grown as a houseplant. Plants from temperate climates, even evergreen ones, do need a period of dormancy that normally coincides with winter and cold temperatures. Preventing them from experiencing this natural process by keeping them as houseplants unnecessarily stresses the plant, can shorten its lifespan and often puts it at risk for disease and insect issues. Plus there is the lack of adequate light and humidity issues that are common to inside a home.

Even bonsai enthusiasts generally summer over their collections outdoors, only bringing them inside when below freezing temperatures are likely. Even then, they are typically maintained in a cool, often unheated location rather than in the warmth of the normal house.