CATALPA: GREAT AMERICAN and INVADER?
The Monday Garden, Eco-gardening at its best
May 1, 2005, Issue 162
The northern catalpa (Catalpa speciosa) is a beautiful, tropical-looking North American native shade tree with a mysterious past. At one time, its range was confined to part of the Mississippi Valley but sources are admittedly fuzzy about which part. Likewise, the name is definitely Native American in origin but there's a big disagreement over which tribal language is the source.
RANGE AND FAMILY: Today, the northern catalpa (Bignonia family) is found through out the U.S.A. and southern Canada, as well as in other countries where it has been imported as a combat-ready urban tree. Also found in temperate urban areas are the northern catalpa's southern Appalachian kin, the southern catalpa (Catalpa bignioides), and its Asian kin – particularly the clearly invasive empress tree (Paulownia tomentosa). Those of you from the southwest might know the southwestern native cousin, desert willow (Chilopsis linearis). Many gardeners are familiar with the lovely orange-flowered native trumpet vine, which is the family's signature member. The Chinese catalpa (Catalpa ovata) is also sold for landscaping.
picture: Northern catalpa in bloom at Stamford High. Stamford CT June 2004
INVADER OR RETURNING ALUMNI? Some say that outside of its native range, the northern catalpa is an invader. My home state of Connecticut has labeled the northern catalpa as having "demonstrated invasive tendencies", which is a no-no of the third degree. (The first degree has been reserved for the worst of the worst, like ailanthus). Being "invasive" means that the plant doesn't come from the area, can escape cultivation and survive on its own, can spread widely, and can out-compete local native plants.