Is it possible to grow bonsai outside, in the ground, and maintain the
small height?

I've written before. I teach at a high school. Our Ecology Club
landscaped an internal courtyard and constructed a Hobbit Hole, with a
round green door, windows, etc. It looks really nice.

I have two bonsai of my own, a variegated Serissa and a fukien tea
teeny
leaf. I'm considering some junipers for around the hobbit hole. The
dirt mound stands roughly 4 ft high. Bonsai would look very nice.
Perhaps they should be kept outside but in pots, pots buried under
mulch
of sorts.

Does anyone have any ideas? Thank you.