Their wide range of sizes, flowering times and flower colour makes them an indespensible plant of every garden. They now come in continuous blooming varieties, dwarf variety, climbing and there are also varieties with vibrant fall foliage colour. Whether you want to dry the flowers for arrangements or just admire them in your garden there is a hydrangea to suit every garden.
Proper pruning is the key to achieving healthy, lush, beautiful Hydrangeas. Hydrangea macrophylla and Hydrangea serrata need pruning to remove dead wood and thin spindly shoots. Late summer is the most popular time to prune since these shrubs only flower on old growth from the previous season. A general rule of thumb is to cut the old, dried flower heads back to the first pair of plump, green buds. To create a fuller plant, remove some of the weaker shoots at the base. By keeping several stems of old productive wood and stout new stems, the shrub will retain a lovely shape and bloom for next season.
Hydrangea quercifolia is a fabulous all‐season beauty, with its unique oak‐leaf shaped foliage, showy flowers, brilliant fall colours, and interesting winter bark. Its pruning requirements are similar to Hydrangea macrophylla and Hydrangea serrata, in that the flowers develop on old wood. Because of this, pruning should only take place when the flowers are finished and periodically removing a few of the older stems to the base to stimulate new growth. Oak‐leaf Hydrangeas are slightly more delicate than other hydrangeas, and prefer a warm, sheltered location with partial shade.
Hydrangea paniculata and Hydrangea arborescens can be cut back hard in spring as these types will produce large blooms on the current season’s growth. If many smaller flowers are preferred, then just a light trim in spring is all that is required. If a mass of blooms that encompasses the shrub is desired, prune stems at various heights. These hydrangeas leaf out later than other varieties, which make these species suitable for colder gardens. Their cream or greenish‐white flowers make wonderful summer displays.
Hydrangeas are plants that enjoy being personalized. It is possible with some hydrangeas to manipulate their colour to suit your garden scheme or simply your personal colour preference.
To achieve blue flowers, the soil must be acidic. We are quite lucky in the Pacific Northwest to have these growing conditions occurring naturally, however if you wish to deepen the colour simply add Aluminum Sulphate to the soil.
To achieve pink flowers the soil must be alkaline. To achieve this you simply add Lime to the soil. Generally it is only the hydrangea macrophylla and hydrangea serrata that change their color. Most other hydrangeas will not.
Hydrangeas are very successful in the temperate Lower Mainland. Many are suitable for growing in containers and respond best to regular watering and fertilizing.