May Tree of the Month-Catalpa
A plant-geek typically has to venture into the city or older suburban neighborhoods and parks to witness the grandeur and beauty of a mature catalpa (Catalpa speciosa and C. bignonioides) in full bloom. The white orchid-like flowers cover the tree in clusters among the large, heart-shaped leaves like a thousand mini bouquets.
Due to its coarse texture and messy cigar-like seed pods, the tree has fallen out of favor in landscapes. Its mature height of 60-70’+ scares away many, as does its tendency to develop “character” with age as the tree matures into an open-irregular shape instead of the picture-perfect rounded canopy that plagues our neighborhoods.
Catalpa speciosa is a Missouri native found naturally in the bootheel area’s streams or bluff bases but also in low or upland wooded areas. The southern catalpa, C. bignonioides is native to southeastern US, but it’s found planted throughout eastern US and the Midwest. The two species are hard to tell apart from a distance. Northern catalpas typically have larger flowers with a notch centered on the lower lobe and slightly ridged bark compared to their southern cousins’ smaller, unnotched flowers and scaly bark. The leaves of southern catalpa emit an unpleasant odor when crushed.
Either species seems to tolerate a range of soils, which is one reason it became a popular option for street trees like sycamore and plane trees February Tree of the Month-Sycamore (garden-lou.com) in urban areas.
Catalpas are sole hosts to the native catalpa sphinx moth larvae, which can defoliate a tree but rarely cause permanent or long-term harm. (Apparently, the larvae are great for fish bait.)
What I love about this plant;
-A mature catalpa in full bloom is a dramatic sight.
-Tolerates a wide range of soils and harsh environments.
-Can obtain character as matures.
-It’s a native!
-Sole host to native moth larvae.
What’s not so great;
-Large, messy seed pods.
-Large size
-Hard to find in trade.
-Some people find the flowers to be a skin irritant.
-The catalpa sphinx moth larvae can cause defoliation, but parasitic wasps usually keep the numbers down, and the larvae rarely cause permanent long-term harm to the tree.
Comments or questions? Email Garden-Lou at gardenloustl@gmail.com
Words and photos by Jo Batzer
© Jo Batzer, garden-lou.com-2024, All rights reserved.
