Emerald Avenue® (‘JFS-KWICB’) European Hornbeam is another great tree from Keith Warren’s tireless work at J Frank Schmidt and Son Nursery. Carpinus betulus Emerald Avenue® has a tight habit of ascending branches around a strong central leader. The dark green leaves are small and disease-free in summer, making this a good choice for street plantings. The fall color is an attractive yellow. Emerald Avenue® tolerates a wide range of soil conditions.