A Pruning Guide for the Catalpa: When, Why & How? MOOWY Meet My Nature Neighbor: The Catalpa Tree Heartspoken The beans pods on the catalpa are nearly as beautiful as the flowers. : r marijuanaenthusiasts While catalpa trees are not generally considered highly toxic, some parts of the tree, particularly the roots, are known to be poisonous according to the USDA Plants Database. The leaves and seed pods Catalpas THE GARDEN WEBSITE.COM How to Grow Catalpa