Wisteria: flowers, characteristics & propagation

Edward
Edward
Edward
Edward

With a passion for growing installed at an early age, I have always been happiest outdoors in nature. After training as a professional gardener and horticultural therapist, I currently run horticultural therapy and community kitchen gardens in the UK, helping others access the many physical and mental health benefits of growing vegetables, fruit and plants.

Favourite fruit: apples and pears
Favourite vegetable: asparagus

With its beautiful pendant flowers, it is no wonder that wisterias are a firm favourite. Find out more about this stunning, pollinator-friendly climber.

Close up of wisteria flowers
When in bloom, wisterias are a highlight of any garden [Photo: nnattalli/ Shutterstock.com]

Often found in parks or historic gardens, wisterias (Wisteria) are well-known for their magnificent display of purple or white blooms. Read on to learn all about wisterias and how to propagate wisteria using different methods.

Wisteria: origin and characteristics

Originally from parts of Asia and the United States, wisterias form part of the Fabaceae family of plants. As vigorous and woody climbers, training wisterias is necessary to keep their long flower racemes and lush foliage looking their best. Wisterias flower from late spring until early summer, and wisteria leaves are alternate, pinnate and deciduous. There are several different wisteria species and varieties to choose from, most growing in excess of 12m tall and requiring ample room. However, if space is at a premium, you can also grow some wisterias in a large container.

Wisteria flowers beginning to open
Wisteria racemes open nearest the stem first [Photo: studio mirage/ Shutterstock.com]

Wisteria flowers

If you are wondering when wisterias bloom, it slightly depends on the species and variety. However, the flowering time of wisteria is generally between April and June. In some circumstances, they can even produce a second flush of flowers later in the summer. Wisterias produce scented hanging racemes of flowers from 10 to 120cm in length, and you can choose between blue-purple, white or even pink flowering wisterias.

Pollinators love wisteria flowers, making these plants a great choice if you are looking for a bee-friendly climber for your garden. When it comes to how long wisterias flower, the blooms tend to last from 2 to 4 weeks. However, this is dependent on the weather, as heavy rain, strong winds or late frosts can damage the blooms.

Purple and lilac wisteria flowers
For a magnificent display, wisterias should be planted in a sunny and sheltered spot [Photo: LifeCollectionPhotography/ Shutterstock.com]

If your wisteria is not flowering, this can be for several reasons, from the plants being too young or not receiving enough sunlight to a lack of moisture or nutrients. Depending on how they are propagated, wisterias can take a long time to bloom. If grown from seed, wisterias can take over a decade to flower, but grafted plants can bloom after roughly 5 to 7 years. Pruning wisterias correctly is also essential for flowering; incorrect pruning can result in fewer blooms. However, if your non-flowering wisteria is mature enough to bloom and is located in the correct place, try applying a sulphate of potash or rose fertiliser to help encourage bud and flower formation. Our Plantura Rose Food is ideal, as it will feed the plant for up to 3 months and, being rich in potassium, promotes flowering.

Rose Food, 1.5kg
Rose Food, 1.5kg
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(5/5)
  • For beautifully flowering roses in pots & flower beds
  • Prevents common rose diseases & ensures healthy growth
  • Long-lasting fertiliser that is free from animal products - child & pet friendly
£12.99

Wisteria in winter: is it hardy?

There is no need to worry about your wisteria in winter, as they are winter hardy. Both Japanese wisteria (Wisteria floribunda) and Chinese wisteria (Wisteria sinensis) are rated H6 for hardiness, meaning they can withstand temperatures as low as -15 to -20 °C. Nevertheless, a late frost can damage the flower buds and care should be taken to avoid planting a wisteria in a frost pocket or exposed location. If a late frost is forecast, drape fleece over the budding stems to protect them from the cold.

Aside from late summer, late winter is also a great time to prune your wisteria. With the leaves having dropped, it is much easier to assess and make your cuts. In February, you can further shorten the shoots previously pruned in August back to 2 or 3 buds.

Pot-grown wisteria in flower
Some wisteria varieties are suitable for growing in containers [Photo: Sally B/ Shutterstock.com]

Propagation

Being such a beautiful climber, you might want to try propagating wisteria. You can propagate wisteria from seed or cuttings, or by layering or grafting. However, you will need to be patient, especially when growing wisteria from seed as they can sometimes take up to 20 years to bloom. It is important to note that wisteria is poisonous, especially the seeds and pods, so be careful and wear gloves when handling any part of these plants.

Wisteria tree with purple flowers
Wisterias are vigorous climbers that can take many years to bloom [Photo: janken/ Shutterstock.com]

Wisteria cuttings

Propagating wisteria from softwood cuttings will produce new plants true to the parent climber. You can take wisteria cuttings in the summer by following the method below:

  • Cut off new growth that is green and not woody early in the morning.
  • Trim the bottom of the shoot so that the cutting is 8 – 10cm long and remove all but half of the top leaves.
  • Place the wisteria cuttings in a pot prefilled with a peat-free cuttings compost, such as our Plantura Organic Herb & Seedling Compost, so that the leaves are just above the soil.
  • Water the compost and cover the pot with a propagator or clear plastic bag to increase humidity levels.
  • Place the pot in a warm and light spot at around 18 °C but out of direct sunlight.
  • Keep the soil moist and remove the cover every few days to let in fresh air.
  • Once rooted, remove any covering and grow on until it has established a good root system and can be potted on.
Organic Herb & Seedling Compost, 20L
Organic Herb & Seedling Compost, 20L
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(4.8/5)
  • Perfect for herbs as well as sowing, propagating & transplanting
  • For aromatic herbs & healthy seedlings with strong roots
  • Peat-free & organic soil: CO2-saving composition
£12.49

Wisteria from seed

You can also grow wisteria from seed. However, when propagated this way, the new plants may not be true to their parents. Once you have collected the ripe wisteria seed pods in late summer or early autumn, you can sow the seeds as follows:

  • Once the wisteria seed pods are completely dry, remove the hard, black seeds.
  • Sow the seeds individually at a depth of 1 – 2cm in small pots prefilled with a seed-sowing compost. Our Plantura Organic Herb & Seedling Compost is perfect as, being low in nutrients, it will encourage germination and root formation.
  • Water gently so as not to disperse the seed, and cover with a propagator lid or cling film.
  • Keep at a temperature of 18 – 21 °C and keep the soil moist.
  • After 1 – 2 months check for germination and remove any lid or covering.
  • Grow undercover and re-pot as required.
  • Harden off and plant out once two sets of leaves are visible and all risk of frost has passed.
Wisteria seed pod and seeds
While it is possible to grow wisteria from seed, you may have to wait 20 years for it flower [Photo: solosergio/ Shutterstock.com]

Placing your wisteria in the right spot can help ensure many years of future blooms. See our related article on planting wisteria for further information and tips.