Hortensie arbustiva - Hydrangea paniculata 'Pink Diamond'

Hydrangea paniculata 'Pink Diamond' is a cultivar of the species Hydrangea paniculata in the Hydrangeaceae family, also known as 'Pink Diamond Shrub Hydrangea'. This deciduous shrub, native to East Asia (China, Japan, Korea), is prized for its large, conical inflorescences, which change from creamy white to deep pink, and for its prolonged flowering from summer to autumn. 'Pink Diamond' is a popular choice for gardens due to its elegant appearance, hardiness and versatility in ornamental landscapes.

Appearance of leaves, flowers and fruits

• Leaves : The leaves are deciduous, dark green , ovate, with serrated edges, 7-15 cm long. They are arranged oppositely on the branches and have a slightly rough texture. In autumn, the leaves may take on yellowish shades, but they are not an ornamental highlight.
• Flowers : The flowers are grouped in large, conical inflorescences (panicles), 20-30 cm long , composed of large sterile flowers and smaller fertile flowers. Initially, they are creamy white (July-August), then gradually turn pale pink and finally deep pink or even red-pink in autumn (September-October), depending on environmental conditions. They bloom on new wood, which allows annual pruning without compromising flowering. The dried flowers remain attractive in winter, adding seasonal interest. They have a faint fragrance and attract pollinators such as bees and butterflies.
• Fruit : Produces small, non-ornamental capsules containing fine seeds. These are aesthetically insignificant and rarely noticeable.

Growth characteristics

• Height and width : It grows as an erect shrub, reaching 1.5-2.5 meters tall and 1.5-2 meters wide in 10-20 years. It has a rounded habit, with sturdy branches that well support the large inflorescences.
• Vigor : Growth is moderate, with dense branching if pruned regularly. It is more resistant than other hydrangeas, adapting well to various conditions.
• Type : It is a deciduous shrub with a branching structure that can be shaped by pruning into various shapes, including hedges or trees.

Growing conditions

• Exposure : Prefers full sun for maximum flowering, but tolerates partial shade . In full sun, the pink color of the flowers becomes more intense, while in partial shade, the inflorescences may remain whiter. A position protected from strong winds is ideal.
• Soil : Grows well in fertile, well-drained soils with constant moisture.

  Hydrangea paniculata 'Pink Lady', unlike other hydrangeas, does not necessarily require acidic soil to grow and bloom well. In fact, this plant is known for its ability to adapt to a wide range of soil conditions, including neutral or slightly alkaline soils. Flower color is not significantly affected by soil pH.

• Watering : Requires regular watering, especially in the first year and during dry periods, to keep the soil moist but not soggy. A layer of organic mulch (e.g. bark) helps retain moisture.
• Pollination : Sterile flowers attract pollinators such as bees and butterflies, contributing to the biodiversity of the garden, although fertile flowers are less accessible.

Care and resistance

• Hardiness : It is very cold-resistant, withstanding temperatures down to -25°C to -30°C (zones 3-9), making it suitable for temperate climates, including Romania. It tolerates cold better than other hydrangeas, and flower buds are rarely affected by late frosts.
• Fertilization : Apply a balanced fertilizer (e.g. 10-10-10) in spring to stimulate growth and flowering. A phosphorus-rich fertilizer in summer can intensify flower color.
• Pruning : Prune in February-March , before new leaves appear, shortening branches to 1/3 of their length or to 2-3 buds to encourage abundant flowering and maintain a compact shape. Remove dead or damaged branches. Unlike other hydrangeas, 'Pink Diamond' blooms on new wood, which makes pruning more flexible.
• Pests and Diseases : May be affected by aphids, mites, or Japanese beetles. Diseases include powdery mildew, leaf spot, or root rot in waterlogged soils. Good ventilation and adequate drainage reduce the risks.
• Propagation : Propagate by branch cuttings taken in summer or by layering . Cuttings are the most effective method to preserve the characteristics of the cultivar.

Use

Hydrangea shrub 'Pink Diamond' is ideal for mixed borders , low hedges , cottage gardens or as a solitary plant in ornamental landscapes. The large inflorescences, which change from white to pink, combine beautifully with plants such as lavender, sage or roses. It can be grown in containers on terraces, being suitable for small yards. Dried flowers are used in floral arrangements, and the winter appearance adds structural interest to the garden.

Origin

Hydrangea paniculata is native to East Asia (China, Japan, Korea), where it grows in forests and on slopes. The Hydrangea cultivar 'Pink Diamond' was selected in Europe, probably in the Netherlands, for its large inflorescences and spectacular color transition. It is one of the most appreciated varieties of paniculate hydrangea due to its resistance and aesthetics, being widely cultivated in temperate gardens.

Cold resistance: up to -40°C
Pot size: 19 cm
Height with pot included: 40-60 cm (varies depending on the season)