Indoor gardens can take many forms. In one garden I designed, I filled a large window with parts of old columns retrieved from demolition sites, cut them to different heights and set out a variety of ferns.
By making the size and shape fit your room, a large planter can be used to provide an instant indoor garden. Place four casters -- the strongest you can find -- on the bottom of the planter. Line the inside with heavy gauge Pliofilm, put down a layer of white stone to reflect light on the bottom of the leaves and retain moisture, and set out your garden in pots. You can rotate or remove a pot and the entire garden can be turned or moved as needed.
Another way to garden indoors is to use hanging plants or basket. Add a wall-to-wall dowel or chrome shower rod across a recessed window and fill it with baskets of flowering or green plants.
Loop the basket hanger over the rod; if it has no loop or hook, hang the baskets from shower curtain rings. To make the baskets cover more glass, simply extend the length of a few pots by adding sections of chain, rope or hangers.
By far the most ambitious indoor garden is a "reverse" greenhouse you can build into your window. With some access to sun, almos any window will do. I call it "reverse" because the ordinary greenhouse projects outdoors from the window, while this alternative projects indoors.
I built my greenhouse in one of two double windows in the master bedroom. To create an alcove deep enough for a 4-foot-deep greenery, I built out storage units on either side, creating ceiling-to-floor clothes closets for the room -- an unexpected bonus for the homeowner.
I chose a wood-framed greenhouse and painted it dark green as a contrast to the white of the new clothes-closet doors. The floor, carpeted in the same deep green, matches the walls. Inside the greenhouse, I put down a strongly reflective white vinyl surface, which is easy to maintain.
The east-facing window provides welcome rays of early morning sun. In addition, it's an ideal growing environment for all kinds of plants and an unanticipated source of heat for the room.