Mass Wisteria

Posted by

Ali Barwani

27 March 2025

On 27 March 2025

Mass Wisteria

We are fast approaching Wisteria season, one of the highlights of the gardening year, when these majestic climbers are festooned with pendulous clusters (or racemes) of purple pea-like flowers. Wisterias are woody vines often to be found adorning homes on many London streets, gracefully trailing above doorways or trained against walls. In parks and large gardens, lilac rivers of wisteria cascade over pergolas and snake through large trees. They are one of those plants that both gardeners and non-gardeners can confidently identify without hesitation.

Traditionally, their flowering season is May to June. However, it feels to me like wisteria blossoming time arrives earlier every year. And in London you will find them in flower from mid-April onwards. Indeed, I have already spotted fat flower buds appearing on several of the potted wisterias in our climbing plants section at Alexandra Palace Garden Centre.

There are eight to ten species in the genus Wisteria, but only four need concern us. Each species has its individual charm, and nowadays there is a diversity of cultivars available to suit every taste and space. Wisterias come in several colours, including pink, white, blue, purple, and lilac.

The most widely planted wisteria in British gardens is the Chinese wisteria (Wisteria sinensis). Originating in China, this graceful climber has long been valued for its scented blueish-lilac flowers. The racemes appear before leaf emergence, making them stand out. Think of chocolate box images of country mansions. The vine’s vigorous shoots clinging to stately homes led to some snobbish commentators (haughty-culturalists?) in the 2000s nicknaming Kate and Pippa Middleton the ‘Wisteria Sisters’ in a burst of obloquy directed against their perceived ‘social climbing’.

American wisteria (Wisteria frutescens) comes from parts of North America. It is a less vigorous and more hardy plant, making it a good choice for small gardens. It was the first wisteria species to be grown in Britain, introduced in 1724. Asian varieties arrived in London from China almost a century later in 1816. Japanese wisterias first reached Europe in

1830. There are two important species from Japan: Silky wisteria (Wisteria brachybotrys) and Japanese wisteria (Wisteria floribunda). The Silky wisteria grows more vigorously and tends to flower earlier than its compatriot. Its racemes are short and broad. The best cultivars are intensely scented. In contrast, the Japanese wisteria is less rampant, and it produces longer racemes.

Did you know there is a fun way to tell the two Japanese species apart? The Japanese wisteria twines in a clockwise direction, while the Silky wisteria twists in an anticlockwise direction. Chinese wisteria also twines in an anticlockwise direction, so with this information you can keep kids occupied for ages trying to figure out which wisteria they are looking at from the direction of turn!

Now is the perfect time to feed your wisteria with a fertiliser rich in potassium and magnesium (such as Vitax Organic Rose Food) to promote flowering. Now is also a good time to plant wisterias before they spring into fresh growth. Plant wisteria against a wall with linear supporting wires or next to a strong frame such as a pergola or trellis, as they do not have tendrils or suckers to attach themselves with. It is important to select a sunny location with a south or west-facing aspect. Wisterias need heat and sunshine to ripen their woody stems for flowering, and to protect the buds from morning frost damage. Choose the spot carefully, wisteria are long lived. The oldest Wisteria at Kew gardens (Wisteria sinensis) arrived as a rooted cutting from China in 1816 and is still thriving there today!

Wisterias are enthusiastic growers. They require pruning twice a year to maintain their shape and to promote flowering. Prune once in January, when you cut back all the side shoots to about a thumb’s length to promote flowering. Did you remember to do this? Really? The second tidy up is in late-July to August, after flowering has finished. Simply tie in any stems you want to retain to extend the plant’s coverage and then remove all unwanted new growth. Following this simple pruning regime will ensure that your wisteria remains controlled and floriferous. Neglect your pruning and wisteria takes over, and this can be costly, not to mention embarrassing. Just ask David (now Lord) Cameron who repaid £680 in 2009 for repairs and maintenance to his second home in Oxfordshire, including the removal of wayward wisteria vines from around his chimney.

But follow the simple pruning rules, and you can enjoy a happy wisteria in your garden for many years to come.

In conclusion, wisterias are stunning plants that add beauty and class to any garden. If you choose the right variety and plant it in a suitable location, then with minimal maintenance, these long-lived climbers will reward you with a spectacular display of colourful blooms year after year.