Hydrangea macrophylla Hamburg

Hydrangea macrophylla 'Hamburg', also known as hortensia, is a classic but effective variety, notable for its large rounded inflorescences measuring 20 to 30 cm (7.9 to 11.8 in) in diameter. Blooming from July to October, the flowers are a deep blue in acidic soil and blue with a touch of mauve to carmine-pink in more neutral soil. These flowers emerge on a medium-sized bushy shrub, adorned with dark green and glossy, strongly toothed, foliage. It will find its place in a flower bed, in a hedge, or in a large pot on the terrace, and will thrive in a semi-shaded and cool exposure with slightly acidic and well-drained soil. It is also an ideal variety for dried flowers, which then take on a wine-like, garnet hue.

'Hydrangea macrophylla 'Hamburg' is a variety obtained through the cross-breeding of hardy species belonging to the Hydrangeaceae family, originally from China and Japan. This compact shrub has a bushy and dense habit, reaching an average height of 1.8 m (5 ft 11 in) with a similar spread. From July to October, its numerous sterile flowers form large round inflorescences, with sepal colours ranging from deep blue in acidic soil, to blue with a hint of mauve in slightly less acidic soil, and carmine-pink in neutral soil. Flowering is accompanied by dark green, glossy, and toothed foliage. This Hydrangea is highly hardy, tolerating temperatures as low as -15 °C (5 °F).

The 'Hamburg' Hydrangea is a generous and sturdy plant, excellent for partial shade. Hydrangeas, beloved by gardeners, are well known for brightening up the north side of houses. This variety will thrive in an east-facing position (morning sun), away from the scorching rays of the summer sun and evening sun, in shrub beds and hedges. It will bring charm and dimension to partially shaded areas of the garden, at a slightly hidden entrance or at the corner of a porch. Although these plants dislike limestone, hydrangeas are not strictly heather plants; they appreciate fertile and clayey soils. Pair them with Magellan fuchsias, annual impatiens, or plant spring-flowering bulbs in front of their round silhouette. Enjoy their splendid flowering in the garden or indoors, and create romantic bouquets with their beautiful inflorescences.

Note: The colour of Hydrangea macrophylla flowers varies depending on the pH of the soil. Traditionally blue varieties turn pink in neutral or alkaline soil. To maintain a beautiful blue colour, mix heather soil or ericaceous compost with your garden soil, and apply aluminium sulphate (contained in slate) or alum stone every spring.