Liliac de vara - Buddleja davidii 'Ellen's Blue' (Butterfly Bush)

Buddleja davidii 'Ellen's Blue' is a variety of ornamental shrub from the figwort family, commonly known as the "butterfly bush." This plant is valued for its spectacular and fragrant flowers, which attract butterflies, bees, and other pollinating insects, making it an excellent choice for gardens aiming to support biodiversity.

Flower Appearance

• Shape: The flowers are small, tubular, grouped in long and dense panicles (large clusters) that can reach 20-25 cm in length. They are arranged at the ends of branches, creating an impressive visual effect and are great nectar producers - a true attraction for bees and butterflies.
• Colour: They have a deep shade of intense blue-violet (sometimes described as a true blue), with a small orange "eye" in the center of each flower, offering a subtle but attractive contrast.
• Scent: It gives off a sweet and fruity fragrance, which enhances its appeal to pollinators and adds a pleasant note to the garden.
• Flowering period: Blooms abundantly from June to October, sometimes until the first frost, especially if faded flowers are regularly removed (deadheading), which encourages continuous blooming.

Growth Characteristics

• Height: Grows compactly, reaching a height of 1.5-2 meters and a similar width, making it smaller and easier to integrate into gardens than other Buddleja davidii varieties.
• Foliage: The leaves are lance-shaped, with a silvery grey-green hue, a fine texture, and a slightly downy underside. They are arranged opposite on the branches and provide an elegant backdrop for the vibrant flowers.
• Vigour: It is a fast-growing shrub but remains well-proportioned, with arching branches that give it a graceful and airy shape.

Growing Conditions

• Exposure: Prefers full sun for abundant flowering but also tolerates partial shade, though with fewer flowers.
• Soil: Requires well-drained soil, from medium to fertile, and adapts to various types (clay, sandy), provided water does not stagnate. Tolerates a variable pH (acidic, neutral, or alkaline).
• Watering: Needs moderate watering; it is relatively drought-tolerant once established but performs poorly in overly wet conditions.
• Pruning: Severe pruning is recommended in February-March, cutting back to 15-30 cm above the ground to encourage vigorous growth and abundant flowering on new wood. Removing faded flowers during the season extends blooming. This pruning also delays flowering, reducing the risk of damage from late frosts.

Care and Hardiness

• Hardiness: It withstands temperatures down to -20°C (USDA zones 5-9), but in colder climates it may die back to the ground in winter, behaving like a herbaceous perennial. In spring, it regrows vigorously from the roots.
• Fertilizing: A balanced fertilizer applied in spring supports flowering but is not strictly necessary in fertile soils.
• Pests and diseases: It can be affected by aphids, mites, or the mullein moth, but is generally resistant if well ventilated. It may develop mildew in damp and poorly drained conditions.

Garden Use

Buddleja 'Ellen's Blue' is ideal for borders, cottage gardens, or as a solitary plant in mixed landscapes. Due to its compact size, it also fits well in containers on terraces or balconies. Its blue-violet flowers combine beautifully with yellow plants (e.g., Kniphofia) or white ones (e.g., white roses), creating vibrant contrasts. It is also excellent as a cut flower, thanks to its fragrance and durability.

Origin

Buddleja davidii is native to China and Japan, where it grows naturally on rocky slopes and disturbed areas. The 'Ellen's Blue' variety appeared as a chance hybrid (chance seedling) of the 'Lochinch' cultivar, discovered in the garden of Ellen Hornig, owner of Seneca Hill Perennials nursery in Oswego, New York, USA. It was officially introduced into horticulture by Heronswood Nursery and received the Award of Garden Merit from the Royal Horticultural Society in 2010, following trials at Wisley, due to its abundant flowering and intense colour.