Every few months I will see displays of items purporting to be terrariums which are actually only a glass pot, no top and no drainage, jammed with tropical plants that will be dead in weeks unless they are lifted out and put into more suitable living quarters. Usually these are in grocery store floral departments, or in a hardware store by the front door where they get blasted with cold air every time the door opens. Poor little fellows, my heart aches to see them.
Take a look at this example:
A rubber tree, a parlor fern, and an alocasia. All beautiful plants, but they get REALLY big, and are so jammed together in this tiny tube that they are battling to the death for the very limited resources available to them. The sweet little tillandsias ionantha mexicana huddled at the bottom might outlast them, if he doesn’t dry out first. There is no top, so it will have to be misted and watered frequently, but there is no drainage, so the roots will most likely rot if the upper part of the plant lives long enough.
Another comment mistake is using succulents. At least there is no top on this glass container, but no drainage is a bad thing for succulents. Many people cover their succulent plantings, only to have the high moisture quickly rot the plant. Check out this post How Not to Plant a Terrarium for in depth discussion on caring for succulents.
The whole point of a terrarium is to provide a high moisture environment for plants that grow in tropical and temperate rainforests, or along streambeds and waterfalls.
I’ve spent many years growing tropical plants, and have been building terrariums for quite a while now. I have several that are around three years old, and still happy and green. Or pink or purple or red, I like colorful leaves … So if you want a Green Mansion terrarium, talk to the Plant Lady!