Each year the Association of Specialty Cut Flower Growers select a woody cut flower of the year. For 2009, the association reached back in time and selected one that was introduced around 1931. Hamburg hydrangea is one of the bigleaf types that were originally native to Japan. This species has been popular for hundreds of years.
The bigleaf hydrangea is often called florist hydrangea. Hamburg is one of the mopheads, or hortensias.
Hamburg blossoms appear on old wood. The roots may survive in colder climates to zone five or so. However, the flower buds can be hit back by really cold weather. For that reason, it is recommended for zones six through nine.
The flowers of Hamburg open in large, rounded, globe-shaped heads. These consist of sterile florets, which are one inch across. The clusters can reach ten inches in diameter.
Hamburg blossoms have large, serrated petals. They begin opening in mid-summer and continue into fall. These appear on tall stems for the plants can be six to eight feet in height.
The color of the blooms depends not only on the pH of the soil but also the age at which the flowers are picked. The color can change as the blossoms get older. Typically these are deep rose, purple, or blue. They tend to display tinges of burgundy as they age.
For fresh flowers, it is best to harvest when the flowers are completely open. Don’t try to rush these flower stems. Give the blooms the time they need to mature, Otherwise the cut flowers are more likely to wilt and won’t have a long vase life. When picked fairly early, they can last for about a week or so. However, by waiting a little later to pick they will last twice as long.
For dry flowers, Hamburg hydrangea can be picked when they’re at their peak. If harvested too soon, the flowers will become wrinkled as they dry. Strip off the leaves and hang the stems up to dry.
Hydrangeas are fast growing plants. They grow well in partial shade as well as sun. In hot climates, some shade is helpful. The plants prefer a fertile, rich, well drained soil high in organic matter. Avoid alkaline conditions as the plants can develop chlorosis. These will grow well in both neutral and acidic soils. They are tolerant of salty conditions, making them suitable for seaside gardens. Keep hydrangeas watered during droughts.