Wisterias are climbing plants par excellence. No matter how it is trained, a wisteria in full flower, with hundreds if not thousands of racemes, cannot fail to excite the beholder.
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Although the most common wisteria are blue-mauve there are also white, pink or purple forms, and while there are some forms of Wisteria floribunda that have only a slight scent, most are highly perfumed adding immensely to their desirability as a garden plant.
Wisteria climb by twining. Some species, such as Wisteria floribunda, twine in a clockwise direction, while others, such as Wisteria sinensis in an anti-clockwise direction. All have a compound pinnate leaf and the flowers, or more correctly inflorescences, are racemes, which vary in length and contain between 20 and 170 individual flowers, depending on species and cultivar. By far the most commonly seen species in the UK is the Chinese wisteria, Wisteria sinensis, which was introduced to cultivation in 1816 and rapidly became popular. The original plant introduced was named Wisteria sinensis ‘Prolific’, and it is still one of the best blue cultivars available, with a gorgeous scent.
IN BRIEF
What Five species and two hybrid groups of vigorous, woody climbers with twining stems.
Origins Most are found in Japan, but wisteria are also native to China and the USA. The three most commonly grown species in the UK are Wisteria floribunda (Japanese wisteria), Wisteria sinensis (Chinese wisteria) and Wisteria brachybotrys (silky wisteria).
Season Most flower April to June, but some can flower as late as July.
Size Wisteria are strong-growing plants that can reach up to 20m, although their eventual size will largely be determined by the allotted space. Wisterias can be kept to a height of 2m if grown on a post.
Conditions In the wild, wisteria are found in woodland areas with their roots in shade and leaves in the tree canopy in full sun. Although happiest in moist, well-drained soils, wisteria will grow in most soils.
Other cultivars worth looking out for are the white-flowered W. sinensis ‘Jako', which has longer racemes and a very powerful scent, especially at dusk when its presence is quite ghostly, and the violet-mauve W. sinensis ‘Amethyst’, one of the most highly scented cultivars.
Whichever wisteria you choose, these vigorous climbers in full flower are a glorious sight to behold and provided you ensure they are grown in the right conditions – and are properly trained and pruned – your success in growing one is virtually guaranteed.
How to grow wisteria
How to train wisteria
Although wisteria is often seen trained along wires on a house or a wall, it can also be extremely effective grown up pergola supports or archways – especially in the case of wisterias with long racemes that are best admired without branches or foliage getting in the way – or as a standard wisteria tree up a post. But no matter how you train your wisteria, the importance of initial training can’t be stressed strongly enough:
- Wisteria are long-lived and will form thick woody stems that will require a sturdy main support. However, only one shoot should be trained up and along this main support.
- If you’re growing against a wall, use strong metal wires (3mm galvanised steel) set at least 45cm apart.
- Check growth throughout the growing season, and again in autumn when the growing season has ended. Where shoots have turned round the wires or posts they should be untwined and tied back to the wire using thin plastic tubing material.
- If two or more main shoots turn round each other, stronger shoots will eventually strangle the weakest, and if shoots are not untwined from the wires it will mean the wire will be part of the main stem when the shoot thickens.
- You can also grow wisteria up a tree, which is a much simpler process. Plant the wisteria some distance from the tree, near the outside branches, and tie jute fillis twine from the plant to the branch. Once the shoot has reached the branches it will then soon make its way into the tree and the fillis twine will rot away.
How to prune wisteria
Many people find the idea of pruning wisteria daunting but it’s not as tricky as it might seem. Pruning is essential for wisteria, not only to keep the plant’s growth in check but also to improve the chance of flower buds forming.
Wisteria should be pruned twice a year, once in summer (July or August) and again in winter (January/February). Read our in-depth guide to pruning wisteria.
20 of the best wisteria to grow
Wisteria sinensis ‘Prolific’
This sweetly scented cultivar is the original W. sinesis introduced from China, and one of the best for growing on a wall. Its soft blue-violet racemes (16-22cm), contain around 50 to 80 flowers.
Wisteria sinensis ‘Amethyst’
A moderately vigorous cultivar from New Zealand. Its racemes, though relatively short (12-18cm), are strongly scented and reddish violet. Leaves are bronze when young.
Wisteria brachybotrys ‘Okayama’
A strongly scented and vigorous cultivar that deserves to be more widely grown. Its leaves are a rich, bronze colour when young, and its racemes (12-20cm) are mauve-purple, with a central white blotch.
Wisteria floribunda ‘Yae-Kokuryu’
Each flower of this distinctive cultivar has 20 petal-like elements, giving it a rich, dark appearance. Its long racemes (33-38cm) have dark violet tips and a faint scent.
Wisteria floribunda ‘Royal Purple’
The darkest-flowered form currently available. Moderately vigorous and sweetly scented, its long racemes (27-40cm) hold more than 90 purple-violet flowers.
Wisteria brachybotrys ‘Shiro-kapitan’
This vigorous plant, the earliest white-flowered cultivar to flower, looks good grown on a red brick wall. Its short (10-20cm) racemes hold 20-35 white flowers, each with a faint, yellow blotch.
Wisteria floribunda f. Multijuga
Best displayed on a pergola, where its long (over 1m), pale-violet racemes can hang down free from any emerging foliage, this is one of the best wisterias available. Vigorous.
Wisteria x formosa ‘Caroline’
When this moderately vigorous, mauve-blue hybrid was first introduced from New Zealand, it was sold as ‘Amethyst’, but is quite different, with longer racemes (17-21cm) and a faint scent.
Wisteria floribunda ‘Lavender Lace’
Sweetly scented, long racemes (42-54cm) with flowers that delicately blend pale and deeper violet colours, make this a good choice for pergolas. Young bronze foliage adds additional interest.
Wisteria floribunda ‘Alba’
Also known as ‘Shiro-noda’, this vigorous cultivar is one of the last to flower. Lovely white fowers with a small yellow blotch and a faint scent. Racemes are relatively long (36-48cm).
Wisteria floribunda Macrobotrys Group ‘Burford’
An excellent cultivar that may belong in the new W. x valderi group. Named from a plant growing on the wall of Burford House, Tenbury Wells. It grows well up a tree.
Wisteria x valderi ‘Eranthema’
A good bluish-mauve hybrid with long (35-45cm), broad racemes offering a wonderful show. Young shoots are brown in colour, a trait inherited from its
W. brachybotrys parent.
Wisteria x formosa ‘Enchantment’
This lovely hybrid, raised by Audrey Menzies in Australia, is very floriferous, and not too vigorous. With moderately long (17-21cm), bluish-mauve racemes, it’s a good form for all types of training.
Wisteria floribunda ‘Lawrence’
This vigorous cultivar, which was selected in Canada, is one of my favourites. It has long (36-50cm), densely packed, blue-mauve racemes and a glorious sweet scent.
Wisteria floribunda Macrobotrys Group ‘Hocker Edge’
A cultivar in the same group as ‘Burford’ and just as attractive. Very vigorous, with long (42-60cm), mauve-violet racemes and a moderate scent.
Wisteria floribunda ‘Kimono’
This delicate-looking cultivar, with whitish flowers on a mauve calyx, is one of the most admired in my collection and a personal favourite. Very floriferous and moderately vigorous, racemes are 35-42cm long.
Wisteria floribunda ‘Rosea’
Also known as Hon-beni this pretty cultivar has soft lavender-pink flowers and a faint scent. Moderately vigorous with longish (32-40cm) racemes, it is one that works especially well grown over a pergola.
Wisteria floribunda ‘Kuchi-beni’
Has a delicate colour, which many people love, and racemes that are 36-45cm long with around 76 to 86 very pale, mauve-pink flowers. Is moderately vigorous and has a some scent. Best not grown in full sun.
Wisteria sinensis ‘Jako’
In Japan this is known as Nioi-fuji, which translates as fragrant wisteria, and it certainly lives up to that name. One of the least vigorous wisterias, with moderately long (25-38cm) racemes.
Wisteria brachybotrys ‘Showa-beni’
A vigorous cultivar that flowers early with shortish (12-20cm) racemes that are a rich mauvish pink. Nicely scented, it’s possibly the best pink cultivar available.
Where to see wisteria
Sir Harold Hillier Gardens, Jermyns Lane, Romsey, Hampshire SO51 0QA. Tel 01794 369317/318
Nymans, Handcross, near Haywards Heath, West Sussex RH17 6EB. Tel 01444 405250,
Witch Hazel Nursery, The Granary, Cranbrook Farm, Callaways Lane, Newington, Sittingbourne, Kent ME9 7LU. Tel 01795 843098. National Collection, open on selected days only.
Where to buy wisteria
Ashridge Nurseries, Grove Cross Barn, Castle Cary, Somerset BA7 7NJ. Tel 01963 359444.
Bluebell Nursery and Arboretum, Annwell Lane, Smisby, Ashby-de-la-Zouch, Leicestershire LE65 2TA. Tel 01530 413700.