Bamboo is the fastest-growing plant in the world, and thrives in an indoor environment; the variety Alphonse Kan (Bambusa multiplex) rapidly reaches 18 feet indoors, while monastery bamboo (Thrysostachys siamensis) reaches 20 feet indoors. The butterfly palm (Chrysalidocarpus lutescens) is a very fast-growing palm tree that can reach 20 feet in height.
Marigolds, which are from the Compositae family, exhibit a rapid growth habit, ultimately growing from 1 to 3 feet tall. They are some of the fastest-growing flowers that can thrive as houseplants and in a variety of conditions and soil types.
Spider plants (Chlorophytum comosum) are some of the fastest-growing house plants. readily sending shoots out to grow, and requiring little maintenance to thrive. Many ivy plants, such as Algerian ivy (Hedera caneriensis), are also rapid growers and are best grown in hanging baskets to allow stems to stretch.