A terrarium, sometimes referred to as a garden under glass, makes a wonderful and impressive gift, even for people who consider themselves plant-challenged. A terrarium is an indoor gardening container, usually made of glass, that is fully or partially enclosed to allow heat and light to enter and confine moisture. Terrariums can be entirely closed but often they are left partially open to allow airflow.
You can make a basic terrarium in less than an hour with very few inexpensive materials. Glass containers, mason jars, and even goldfish bowls make beautiful terrariums and miniature terrarium plants might only cost a few dollars each.