Dog walk treasures (Catalpa pod) SIDEWALK NATURE 92,403 Northern Catalpa Seeds Royalty Free Images, Stock Photos & Pictures Shutterstock No these aren't giant tree green beans, but instead the seed pod of the northern catalpa. These bean like pods can grow to be 20" long and contain numerous 1" long seeds. #haverfordcollegearboretum # The Northern Catalpa Tree Nebraskaland Magazine Winter Trees and Shrubs: Northern Catalpa awkward botany