Amarilis

Like paperwhites, an amaryllis can be grown in a watertight container. (You can buy an inexpensive enamelware pot like the one shown here at many hardware stores.)

How to plant: Layer pebbles, rinsed aquarium charcoal, then more pebbles, until you've filled about two-thirds of the container. Pour in enough tepid water to just cover the pebbles, then add another thin layer of pebbles. Set a single bulb (or more, in a larger container) on top, root-side down; be sure to leave on the fleshy roots for quick, healthy growth. Scoop in more pebbles, until they reach the point where the bulb narrows; this will help stabilize the plant as it grows. Once a week, work a finger down to feel the roots; if they don't touch the water, add more.

You'll see blooms: In six to eight weeks, sometimes sooner. Once a bulb has been forced, you should discard it. Getting it to bloom again can be difficult.