Basic Information

Common Name: Catalpa

Scientific Name: Catalpa

Native Habitat: Eastern North America and East Asia

History / Discovery / Cultivator

The genus Catalpa comprises about ten species of deciduous trees, easily recognized by their large heart-shaped leaves, showy white or yellow flowers in panicles, and long, bean-like seed pods. The name “Catalpa” is derived from the Catawba Native American name for the tree, “Kutuhlpa.” While the exact history of discovery isn’t attributed to a single individual, the trees have been known and utilized by indigenous populations for centuries. Their historical range encompassed areas inhabited by various Native American tribes, who used the wood for construction and other purposes.

The eastern catalpa (Catalpa bignonioides) is native to the southeastern United States. It was introduced to Europe in the 18th century and quickly became a popular ornamental tree due to its attractive flowers and relatively fast growth. The western catalpa (Catalpa speciosa), which is native to the Midwestern United States, was later recognized as a distinct species. It possesses larger flowers and longer seed pods compared to its eastern counterpart.

Catalpas have a history of cultivation beyond ornamental use. The hardy catalpa (Catalpa speciosa) became significant in the late 19th and early 20th centuries as a “catalpa plantation” resource grown by the U.S. government and railroad companies. Its wood, which is lightweight and resistant to rot, was highly sought after for railroad ties, fence posts, and other applications requiring durable lumber in contact with the ground. These plantations, while somewhat successful, ultimately faced challenges due to varying soil conditions and the advent of more durable treated wood alternatives. The quick growing of the tree made it an attractive alternative where slow growing hardwoods like Oak would take much longer.

The introduction and cultivation of catalpas in Europe and other parts of the world were driven by their aesthetic appeal and potential economic value. Their showy blossoms and adaptability to various climates contributed to their widespread planting in parks, gardens, and along avenues. The trees natural resistance to deer make it a great planting option where deer are present. Today, catalpas remain popular ornamental trees, admired for their beauty and historical significance. Their impact on forestry and railroad industries in the past continues to be a testament to their versatility and utility. The trees have also escaped cultivation in many areas, naturalizing beyond their native ranges.

Plant Care Summary

Botanical Insights

Adaptations

Catalpas possess several notable adaptations. Their large leaves provide a broad surface area for capturing sunlight, facilitating rapid growth. The tree’s tolerance to a wide range of soil conditions allows it to thrive in diverse environments. The distinctive long, bean-like seed pods serve as a dispersal mechanism, aiding in seed distribution by wind. Catalpa speciosa is notably hardy and can grow quite rapidly even in poor soil. They also produce a chemical called catalpol, which helps protect them from insect predation.

Propagation Methods

Catalpas can be propagated through several methods:

• Seed: Seeds can be collected from mature seed pods in the fall and sown in the spring after stratification (cold treatment).
• Cuttings: Stem cuttings can be taken in the summer and rooted in a well-draining medium.
• Root Suckers: Catalpas may produce root suckers, which can be carefully dug up and transplanted.

Toxicology

While generally considered non-toxic, ingestion of catalpa leaves or seed pods may cause mild gastrointestinal upset in humans and pets. Symptoms may include nausea, vomiting, and diarrhea. The severity of the reaction is typically mild. It is always advisable to keep plants out of reach of children and pets to prevent accidental ingestion. Contact a veterinarian or medical professional if you suspect poisoning.

Common Problems

Pests:

• Catalpa Sphinx Moth (larvae can defoliate trees)
• Aphids
• Spider Mites

Diseases:

• Powdery Mildew
• Verticillium Wilt
• Leaf Spot

Other:

• Leaf Yellowing: Can be caused by nutrient deficiencies or poor drainage.
• Branch Breakage: Catalpa wood is relatively brittle and susceptible to breakage during strong winds or heavy snow.
• Root Bound: Catalpas should not be planted in close containers, as they will become root bound and eventually die.

Rarity & Value

Rarity:

While catalpas are not generally considered rare in cultivation, certain cultivars or varieties with unique characteristics (e.g., unusual leaf color or flower form) might be less common. Mature specimens of Catalpa speciosa are found less often in urban environments than the more compact Catalpa bignonioides.

Value:

The value of a catalpa tree typically depends on its size, health, and aesthetic appeal. Mature, well-formed specimens with abundant flowers can command higher prices. Cultivars with desirable traits (e.g., variegated foliage) may also be more valuable. In addition, the tree is important for use as caterpillar food by the Catalpa Sphinx Moth, who larvae are a great fishing bait.