I love the tall 'Limelight' Hydrangea (Hydrangea paniculata 'Limelight') for its beautiful and reliable white/lime green flowers, fast growth and easy care. You cannot go wrong with this plant if you have room for it. It is hardy to Zone 3, can grow to 10 feet tall and thrives in full sun or partial shade. It makes both a wonderful cut flower and landscape plant. You can even prune it into tree form.