Catalpa speciosa, commonly known as the northern catalpa, is one of the most easily recognizable trees of the eastern forests. Reaching heights of 40 to 75 feet at maturity, this large, hardy species is well-suited for planting in Nebraska. Known for its larger-than-life leaves, often up to 8 inches wide and a foot long, the tree is an exceptional source of shade. In late spring (typically late May to early June in eastern Nebraska), clusters of large white flowers cover its branches, later giving way to long, slender seed pods in late summer and fall. These distinctive features make the tree easy to identify throughout the growing season, even from a distance. Its adaptability to a range of soil types and tolerance of urban conditions further contribute to its popularity.
Beyond its aesthetic appeal, the northern catalpa plays an important ecological role. Its flowers serve as a key source of nectar for native insects, supporting critical biodiversity within our eastern forests. When many people hear the word “pollination,” they picture bees and butterflies dancing between sunlit blooms. While familiar, this represents only a
fraction of the activity occurring in forests and wild areas. Moths, bats, fireflies, and other nocturnal animals are also prolific pollinators, carrying out essential work that often goes unnoticed.
Trees and other plants employ a range of strategies to maximize pollinator visits, as increased pollination improves seed viability. Species pollinated primarily by nocturnal animals often emit strong fragrances to attract pollinators in low-light conditions. In contrast, plants that rely on daytime pollinators typically feature bright colors and nectar guides, markings that direct pollinators to the flower’s nectar.
Some plants, however, have evolved to take advantage of both strategies. The northern catalpa is one such example. Its large, bell-shaped flowers display vivid orange and purple markings that lead into the nectary, where nectar is stored. These markings guide bees, birds, and other daytime pollinators, facilitating pollen transfer between blooms. As evening falls, the tree shifts its strategy, increasing nectar production and releasing a strong, sweet fragrance that attracts nocturnal pollinators, including the catalpa sphinx moth, a specialist species that depends on catalpa trees for survival. Its caterpillars, commonly known as “catalpa worms” are even prized by anglers as effective bait.
This ability to attract pollinators across the full 24-hour day makes the northern catalpa especially valuable within its ecosystem. It supports a broader range of species and increases the likelihood of successful reproduction in challenging environmental conditions.
This dual pollination strategy, supporting both daytime and nighttime visitors, has helped the northern catalpa become a resilient and valuable component of eastern forests, in both urban and rural landscapes. By bridging the gap between diurnal and nocturnal ecosystems, it sustains a wider range of wildlife than many other tree species. In doing so, the northern catalpa stands not only as a striking presence in the landscape, but as a reminder of the intricate and often unseen relationships that sustain the natural world.
