Purple Reign

In full bloom, it’s a glorious sight. Graham Ross explains how to grow, train and prune wisteria.

In the early 19th century, two distinct wisteria species found their way to Australian shores. Chinese wisteria (Wisteria sinensis) was the first to arrive, introduced in 1825 by Alexander Macleay, Colonial Secretary for New South Wales, who cultivated it in his garden at Elizabeth Bay, Sydney. Nearly two decades later, in 1843, the little-known Wisteria frutescens from America, featuring short, compact and lightly scented flowers, made its appearance in Australia, courtesy of William Macarthur, who grew it at his nursery at Camden Park, NSW. Despite its introduction, Wisteria frutescens quickly fell into obscurity and eventually yielded ground to the widespread cultivation of the Chinese wisteria.



Garden tourism in the 21st century has reawakened interest in the Japanese wisteria, Wisteria floribunda. Deeply embedded in the Japanese psyche, it shares equal status to the revered Japanese flowering cherry. In Japan, wisteria is called ‘Fuji’, a reference to sacred Mount Fuji. The venerated ‘Tale of the Genji’ by Murasaki Shikibu, written in the early 11th century, mentions a 'wisteria pavilion' as a focus for gatherings. Wisteria has been cherished in Japan for centuries; the oldest fabric (Fuji-fu) is still made today from wisteria fibres.



After 38 years of cherry blossom tours, Ross Tours operated our first ‘wisteria’ tour (in 2018) to discover the hugely impressive wisteria tunnels and enormous wisteria ‘trees’ growing in Japan.



While the Chinese wisteria is still the most popular, the Japanese species is the oldest in cultivation, with flowers racemes three times the length of its Asian neighbour.

How to Grow

• Source your wisteria from a quality garden centre to ensure accuracy of naming.

• Plant wisteria in full sun.

• Soil should be well drained, clay loam with added organic matter or compost.

• Don’t prune young plants for three years. Instead, focus on training young shoots.

• Once fully established, prune after flowering by shortening stems back to 3-4 buds.

• Prune twice a year; after flowers (November) and again late summer (February). Pruning any later will remove flowering wood.

• Later in spring, remove dead, crossing branches and untidy internal growth.

• In early summer, remove whippy thin growth completely.

• To avoid suckering, don’t cultivate around base of plant.

 

Growing Tips

Wisteria is a strong twining plant which can grow to 20m if left unchecked. Training is the key to success.

• As a wall plant, the stems can be trained along wires (3mm) and spaced 45cm apart.

• Check growth regularly during the growing period and again in autumn after the growth season. Strong stems will strangle weak stemsif they are allowed to entangle.

• Arches can support wisteria if they are strong enough. Well anchored reinforced steel mesh is suitable

• Low fences need to be strong to support wisteria. Use stout 1-1.5m posts concreted at base, spaced at 4-5m intervals with strong galvanised wire (marine grade) along which stems can be trained.

• Standard wisterias may be grown in large strong timber planters (as we see in Japan). These single stemmed ‘mini-trees’ are trained to a singlestem, not grafted, with a canopy of 2-3m. They grow 2m tall and display flowers to perfection.They would suit large ornamental pots and should be repotted every 4-5 years (in autumn).

• Pergola construction should be strong and durable to withstand the enormous inherent strength of the wisteria. Metal or timber posts with secure joinery are essential. Railway sleeper sized hardwood beams on substantial posts make for a permanent, trouble-free structure.
  
   

Wisteria varieties

Chinese wisteria (W. sinensis)

Flowers are sweetly perfumed, blue, white and mauve with short stout racemes, up to 30cm. The stems twine in anticlockwise direction. Popular in bonsai because of the shorter inflorescence

• W.sinensis: vigorous, strong scented lavender

• W.sinensis ‘Jako’: powerful scent, especially in the evening, white with mauve edge

• W.sinensis 'Alba': pure white

 

Japanese Wisteria (W. floribunda)

Synonymous with W. longissima, with long racemes of scented flowers that last longer than W.sinensis, in purple, pink, mauve, blue, white, cream; singles and doubles. Delicate tapering flower stems grow up to a 1m or more in length. The stems twine in a clockwise direction.

• W.floribunda ‘Alba’ (syn ‘Shiro-noda’): 40cm, fragrant white

• W.floribunda ‘Bayou’: 25cm, less vigorous, scented violet blue

• W.floribunda ‘Geisha’: 35cm, scented lilac

• W.floribunda ‘Kuchibeni’ (syn Carnea): 40cm raceme, fragrant, pastel pink

• W.floribunda ‘Rosea’: 40cm, fragrant, pale rose pink tipped purple

• W.floribunda ‘Royal Purple’: 30cm, deep purple, sweet scent

• W.floribunda‘ Violacea Plena’ (syn ‘Black Dragon’): 40cm, double lilac

American wisteria

Whichever wisteria you choose, in full flower it willbe a glorious sight, with a scent especially at dusk. Sunshine, training and pruning are the keys to success.

• W..frutescens ‘Amethyst Falls’ : 20cm, double, deep lilac, slight fragrance

W.brachybotrys ‘Shiro-kapitan’ (syn W.venusta): 15cm, vigorous, fragrant, larger pure white individual florets

WHERE TO BUY

NSW

Bonnyrigg Garden Centre, Bonnyrigg (02) 9610 5366

Heritage Gardens Nursery, East Maitland (02) 9953 8361

Honeysuckle Garden Centre, Mosman (02) 9953 8361

Honeysuckle Garden Centre, Turramurra (02) 9487 3888

Welby Garden Centre, Welby (02) 4872 1244

Wyee Nursery Garden Centre, Wyee (02) 4357 1190

ACT

Greengold Garden Centre, Nicholls (02) 6230 2000

Heritage Nursery, Yarralumla 0448 007 207

Willow Park Garden Centre, Pialligo (02) 6248 9095

VIC

Acorn Garden Centre, Surrey Hills (03) 9890 3162