Description

A member of the Trumpet-creeper Family (Bignoniaceae), northern catalpa is a perennial deciduous tree which readily grows in USDA Hardiness Zones 4 to 8.  The height at 20 years is about 20 feet.  The tree bark ranges from scaly to ridged, to blocky plates.  On young tree seedlings the bark is thin and easily damaged by impact, or rodents. Twigs in winter have a unique identifying characteristic.  They have sunken leaf scars which resemble suction cups.  Their whorled arrangement of 3 scars per node is another trait easily identified. Leaves are simple, large ovate to ovate-oblong, from 8 to 12 inches long, heart-shaped tropical looking without any lobes and are yellowish green in color.  Leaves are generally opposite on large branches and often whorled in 3 on young stems.  They turn an undistinguished yellow in the fall before dropping.  The flowers of catalpa are perfect.  Flowering takes place in late spring to early summer.  They occur as large clusters of showy, white, bell-shaped corollas of 5 lobes with ruffled edges and yellow, orange or purple interior spotting or streaking.   Individual flowers are showy, tubular up to ½ inch broad.  They are branched in about 10 inch clusters at the stem tips. 

Seedpods are slender and green in the summer growing from 10 to 24 inches long, looking similar to an exaggerated green bean.  They mature in the fall, turn dark brown, split open lengthwise to let seeds fall in the spring.  The shape and color of the mature seedpod gives rise to the common name of cigar tree. 

Adaptation

Catalpas prefer moist, deep, well-drained soil, but adapts to dry or wet soils.  It prefers an open sunny space to partial shade.  It is tall with an irregular, open-rounded to narrow-oval crown.  This tree comes into leaf very late in the spring and it is one of the first to lose its leaves in the fall.  Its longevity is about 60 years. It has been extensively propagated for over 200 years.  It can now be found in most states east of the Rocky Mountains and in Utah. 

Uses

Northern catalpa is primarily used today as a large ornamental shade tree.  It is widely planted in urban areas as a street and lawn tree.  Conservation uses include plantings in mined-land reclamation projects and shelterbelts.

References

Geyer, W.A., & Row, J. (2006).  Plant fact sheet for northern catalpa (catalpa speciosa).   Retrieved from http://plants.usda.gov/java/factSheet