Step 1 : Introduction to the question "What color are the leaves of birch, tulip poplar, redbud and hickory trees in autumn?"
When the leaves of trees such as redbuds, birches, tulip poplars and hickory always turn yellow in the fall, never red. There is apparently no biological significance or function to the shift in color. There are a few trees, such as dogwoods, black gums, sugar maples and sourwoods that usually turn red but they may, on occasion, be yellow as well. The most intense color shifts in fall foliage take place in areas such as New England in the northeastern U.S. Source: NCNatural.com
