Sometimes referred as “cigar tree” because of its intriguingly long seed pods, northern catalpa draws the eye in all seasons. Heavy, upright clusters of fragrant, white to lavender, trumpet-shaped flowers appear May through June at the branch tips. The yellow-and-purple-accented flowers are followed by dangling, green-bean-like seed pods that persist through winter (another common name is Indian bean tree). Heart-shaped, yellowish-green leaves grow up to 12 inches long and 8 inches wide, turning yellow in fall. In full or part sun, this versatile tree grows up to 60 feet tall in a wide range of well-drained to wet soils, and it tolerates occasional flooding and extremely hot, dry conditions. The leaves may scorch and drop during droughts. The trunk and branches of this tree are thick and tend to twist, offering strong winter interest and making it popular as a climbing tree. The twigs have a unique identifying characteristic that helps with tree identification during winter; look for sunken leaf scars that resemble suction cups in a whorled arrangement of 3 scars per node. 
 
Northern catalpa is highly valued for its grandiose attributes and rounded, symmetrical form in both yards and parks. It’s also used as a land-reclamation tree and soil stabilizer because it will grow successfully in places where air pollution, poor drainage, compacted soil, and/or drought can become a problem for other species. It produces lots of shade and grows at a fast rate once established (2 to 3 feet per year), with growth slowing as it matures and increases in spread. It typically begins to flower about 7 years after the tree sprouts and will live an average of 60 years. 
 
Catalpa requires thoughtful siting and a bit of maintenance. It has an extensive root system, and it sheds large leaves, flowers, and seed pods (which could lead to many more catalpa trees), making it a poor choice for siting near septic systems, foundations, property lines, fences, or parking areas. The limbs tend to droop as the tree grows, and street trees may require pruning for vehicular or pedestrian clearance beneath the canopy. Hard pruning can transform the tree into a bushy shrub with magnificent foliage, or the plant can be lightly pruned to improve the structure. 
 
As the sole host plant for the catalpa sphinx caterpillar, northern catalpa (aka caterpillar tree) is sometimes so covered with caterpillars that the entire tree is defoliated. The hardy tree recovers and leafs out the following spring, but it can’t withstand this abuse year after year. Thus, it evolved a defense system. The leaves of catalpa have extrafloral nectaries, or glands that excrete sugary nectar. When the leaves are being eaten, nectar production increases dramatically and draws the attention of ants. To protect this new food source, the ants drive away the caterpillars. Ladybird beetles, tachinid flies, and other beneficial predators participate by attacking eggs and young larvae. As for the adult caterpillars, humans often collect them as fishing bait because their tough skin is easy to hook, and they ooze a green fluid that is enticing to fish. 
 
Native habitats include low-lying areas and open areas along streams, rivers, and lakes. This is a great shade tree for large spaces. It can add a tropical look to the landscape while protecting understory plants from sunscorch.   
 
Plant Characteristics: 
Reaches 40-60’ tall with a 20-40’ spread. 
 
Grows in part or full sun. 
 
Grows in alkaline or acidic, loamy, rich, sandy, clay, silty loamy, well-drained soils in a wide range of moisture conditions. 
 
White, bell-shaped, five-lobed corollas with ruffled edges appear spring and early summer. Individual flowers are ½” across. Green seed pods follow in summer, growing 10-24" long. They turn dark brown in fall, splitting open to let the seeds fall in the spring. 
 
Opposite, spade-shaped leaves with smooth margins and pointed tips grow on stout, smooth, orange-brown or gray twigs. 
 
Trunk grows to a diameter of 3-4’ with light or dark brown, deeply furrowed bark. 
 
Wildlife Value: 
Catalpa is a host plant for 10 species of Lepidoptera, including the horned spanworm moth. The flowers are a valuable source of summer nectar for hummingbirds and numerous species of native and honey bees. 
 
Medicinal, Edible, and Other Uses: 
Bark (though not root bark) can be made into a tea that Native Americans used as a laxative and for snake bites. While the seed pods are not considered edible, some use them as a diuretic and to treat skin infections. 
 
The flowers are used for honey production. 
 
The wood has historically been used for fence posts and railroad ties because of its resistance to rot. It’s now used to build compost bins and raised-bed frames.