One visit to your local garden center and it's clear that mophead hydrangeas (Hydrangea macrophylla) are very popular. While pink or blue flowers have been the most popular colors, plant breeders also have been working on new red selections. Up until now, most red hydrangeas have produced flowers that are more lavender or deep pink. However, 'Hornli' breaks the mold. Hydrangea macrophylla 'Hornli' produces fire engine red flowers on a dwarf plant that's perfect for a container or flower garden. 'Hornli' grows only 2 feet tall and wide and produces 3-inch-diameter blooms on old wood, so it will need protection in colder areas. It's hardy in USDA zones 6 to 9.
For more information about 'Hornli' hydrangea, go to: Park Seed.