You won't find any healthy colors here besides green, but the textural ripples and wrinkles on the leaves of Peperomia caperata 'Variegata' an intriguing contrast to other terrarium plants patterned with color. This plant stays about 6 inches tall and likes the low but regular light and moist conditions of a closed terrarium. Divide it for a friend—or another terrarium—by taking a leaf cutting.

Name: Peperomia caperata 'Variegata'

Size: To 6 inches tall and wide

Terrarium Tip: According to Martin, you can help your terrarium thrive by layering in 2 to 3 inches of potting soil, then planting. Martin avoids landscape fabric between the layers. "I try to create something more like nature and less like control," she says.

Buy It: Peperomia caperata, $6.50, Taylor Greenhouses