Wisteria floribunda ‘Violacea Plena’

Description

There are Wisterias that impress, and there are Wisterias that genuinely surprise — and ‘Violacea Plena’ falls firmly into the second category. This is the double-flowered Japanese Wisteria, and if you have never seen it in bloom, the flowers are not quite what you would expect. Rather than the familiar open, pea-like blooms of the classic forms, ‘Violacea Plena’ produces fully double flowers in dense, rounded clusters of deep blue-violet — each raceme a rich, textured column of rosette-like blooms that has more in common with a bunch of small grapes than a traditional Wisteria flower. It is unusual, it is beautiful, and it is unlike anything else you can grow on a wall or pergola.

The flowering season falls in late spring and early summer, and the display — while perhaps a little shorter than some single-flowered forms — is generous and deeply coloured, the blue-violet tones among the richest and most saturated in the Wisteria family. Fragrant, distinctive, and full of character, this is a plant for the gardener who loves Wisteria and wants something that goes a step further.

A talking point in every sense — ‘Violacea Plena’ is the Wisteria that makes people look twice.

Quick Facts

– Plant type: Deciduous climbing shrub
– Flowers: Fully double, deep blue-violet — produced in dense, textured racemes in late spring and early summer; sweetly fragrant
– Position: Full sun for the richest flower colour and most generous display
– Soil: Moist, well-drained, moderately fertile
– Hardiness: Fully hardy
– Eventual size: 6–9m with support — vigorous and rewarding with consistent pruning
– Support needed: Sturdy pergola, robust trellis, or strong wall wires — essential from planting
– Best for: Pergolas, sunny walls, large arches, and any garden where something a little unexpected and truly distinctive is wanted

Caragh Garden Notebook

‘Violacea Plena’ is one of the oldest and most celebrated of the Japanese Wisteria cultivars — a variety with genuine history and character that has been grown and admired in gardens for well over a century. The double flowers are its defining quality, and up close they are extraordinary — each bloom a tightly packed rosette of deep blue-violet petals that gives the whole raceme a lush, almost luxurious density quite unlike any single-flowered form.

The stems twine clockwise in the Japanese manner, and the plant is as vigorous and rewarding as any in the floribunda group when given the right conditions and consistent pruning. The deep colour of the flowers is shown at its very best in full sun — in shadier positions the blooms can appear a little washed out, and the display is rarely as generous. A warm, sunny wall or a well-positioned pergola is where ‘Violacea Plena’ truly comes into its own.

Because the flowers are double, they do not set seed in the way that single-flowered forms do — which means the plant puts more of its energy back into growth and flowering rather than into seed pod development. For some gardeners this is a small but welcome bonus.

Caragh tip — the one that matters: As with all Japanese Wisterias, twice-yearly pruning is the foundation of a great flowering display. Cut the new season’s long shoots back to five or six leaves in summer, and cut those same shoots back to two or three buds in winter. The double flowers of ‘Violacea Plena’ are produced on short spurs close to the main framework — the more consistently and carefully those spurs are built up over the years, the more extraordinary the display becomes. This is a plant that genuinely rewards the gardener who takes the pruning seriously.