Catalpa speciosa flowers, leaf, and bark (Public Domain) Catalpa trees will grow quickly and can reach heights of up to 80 feet. The average and expected height of most Catalpas will be around fifty feet. This tree grows the quickest during its first ten years, reaching about twenty feet tall before it slows down. The Catalpa is a deciduous tree whose varieties can grow nearly everywhere in the United States. Northern and Southern Catalpa varieties available for purchase as either seeds or saplings Visually, and feature-wise, you'll notice its blooming white flowers in the spring. Creating a unique look not seen on many trees. Especially not on trees that can grow as large as the Catalpa. Also, later in the season, you'll see the development of its seed pods. When autumn comes, the leaves of the tree will turn brown and fall off once the first heavy frost occurs. Along with its seed pods. Some consider the Catalpa tree, with its flowers, to be an ornamental t...