Hydrangea : Basic Care

Hydrangea macrophylla is a species of flowering plant in the family Hydrangeaceae, native to China and Japan. It is a deciduous shrub growing to 2 m (7 ft) tall by 2.5 m (8 ft) broad with large heads of pink or blue flowers in summer and autumn. Common names include big leaf hydrangea, French hydrangea, lacecap hydrangea, mophead hydrangea, penny mac and hortensia. It is widely cultivated in many parts of the world in many climates. It is not to be confused with H. aspera 'Macrophylla'.

Hydrangea

At a minimum, hydrangeas must be given weekly water. In hot summer months, their leaves quickly show signs of heat stress, but are easily revived with cooler temperatures or by misting their leaves. Hydrangeas usually do best in filtered shade, protected from hot southwest exposure, although they may grow luxuriously given full sun in cool, foggy coastal areas. In the winter, when the plants have dropped their leaves for dormancy, we prune hydrangeas for size control. Stems are pruned back to buds on strong growth, leaving stems about four feet tall; they can be pruned lower if there is a need for a more compact size, but they will produce fewer blooms the next season. Any dead or weak growth and old canes should be removed entirely, down to the plant’s crown, to encourage the renewal of strong new flowering stems. Be aware that hard renovation pruning can remove the next season’s flower buds, which form the year before. If buds are not removed, hydrangeas will bloom from July to November, on the ends of new growth. Regular fertilization can greatly enhance the summer display; Filoli gardeners apply a general fertilizer, such as 10-10-10, in the fall to encourage root growth, and in the spring when the plants break dormancy.

Hydrangea

Color Play

The color of hydrangea blossoms, which varies from white to pink, blue, and chartreuse, can be changed or enhanced by applying amendments that alter soil pH. Blue flowers are the product of acid soil in the range of 5.2-5.5; in November, 1/4 - 1/2 lb of aluminum sulfate around the base of large plants, and lightly cultivate it into the organic mulch at the base of each plant. Be aware that if aluminum sulfate is applied to white or pink hydrangeas, it will turn pink hydrangeas blue but have no effect on white blooms.

Dried Flowers

Another wonder of hydrangea blossoms is how beautifully they dry; people remove some choice blooms in late summer, into early fall, when the tiny, inconspicuous flowers are fully open and their texture changes from succulent to leathery. If they are too soft with moisture, the heads don’t hold their shape and color.

For drying, leaves are removed and flowers are left upright—or hung upside down for weak stems—in a warm, dry room. Once they are completely dry, they make colorful additions to arrangements later in the year when other flower selections are slim. During the winter holidays, people often use them to make wreaths and for decorating garlands and trees. Fresh flowers are also picked in season, conditioned in warm water and used in fresh arrangements throughout the house.

Reference : Hydrangea Care