Most tropical plants have adapted the ability to grow quickly in order to compete with other plants and pests in their environment. In tropical areas where there is never a frost, no dormancy period is needed, or the wet season is very short so all the growing has to be done in a small time frame before the dry season begins. Many of these fast-growing plants have become an important agricultural product for food production and industry. Many are finding new life as crop plant because of their potential use in biofuels and their ability to restore ecosystems.
Leucaena leucocephala, commonly known as leadtree, is a fast-growing tropical tree used for reforestation projects, river bank restoration and cattle feed. The plentiful seeds are a potential source for biofuels because of their high oil content. Leadtrees produce abundant foliage for ruminant feed, and its yield per acre is twice that of alfalfa. Leadtree absorbs toxins from the soil and improves farmland over time, improving production in companion crops like coffee, where it is used to also shade the plants. Because it grows to 65 feet tall, it makes a good windscreen for farms.
Polygonum cuspidatum is a very fast grower that is also considered invasive to some areas. It looks very much like bamboo. It has reddish green canes and spreads like bamboo, by underground rhizomes that reach out 60 feet from the plant. Canes sprout up and flower along the rhizomes, releasing wind-borne seeds that readily germinate. It can quickly take over an entire stretch of riverbank field or any moist areas that aren't heavily grazed by livestock. It can exploit cracks and grow through several inches of asphalt or concrete. In many areas the soil has to be completely sterilized to remove any trace of the plant before construction can begin. The tender shoots are edible and can be cooked and eaten like asparagus spears.
Ricinus communis is a fast-growing tree that can reach up to 42 feet tall in tropical and subtropical areas. In cooler climates it is grown as an annual and can reach up to 10 feet tall in one season when grown from seed. Because of its rapid growth, it depletes the soil quickly and needs to be heavily fertilized. When it is grown for crop production, it is usually rotated periodically with other crops so the soil does not get too depleted. The beans have a very high oil content and are the source of castor bean oil. It is used for medicinal treatments as well as many manufacturing processes, including lubricants, waxes, candles and fabric dye.