After a five-year wait, a magnificent scented wisteria has burst into bloom at RHS Garden Wisley in Surrey.
The Wisteria Walk, planted in 2018, has already proved a spectacle with its white-flowered Wisteria ‘Kimono’. However, the beautiful purple Gardeners often use the word variety when referring to a specific plant, but the correct botanical term is 'cultivar'. Whichever word you use, it means a distinctive plant or plants, given a specific cultivar name and usually bred to enhance certain characteristics, such as flower or fruit size, colour, flavour or fragrance, plant size, hardiness, disease resistance, etc. Additionally, it is worth knowing that, botanically, variety has another meaning - it refers to a naturally-occurring distinct plant that only has slight differences in its looks. For example, Malva alcea var. fastigiata differs from typical plants by having an upright habit.
This year, with fewer frosts predicted, the team went to extraordinary lengths to nudge this tender beauty into bloom by keeping night vigils with warming fires to keep the cold at bay.
Now, for the very first time and thanks to the dedication of the horticultural team, this is the spring when we can finally enjoy the breath-taking two-tone display in all its glory.
Pushing boundaries
In 2018, two special cultivars were selected to adorn the wisteria arch, inspired by a visit to the national collection in Kent. Curator Matt Pottage and his team were in search of outstanding scent, rich, two-tone colour and luxuriously long racemes of flowers, which would hang down into the walkway to provide a wonderfully sensory experience.
The chosen candidates were a stunning blue-tinged white variety called ‘Kimono’ and an opulent purple variety called ‘Kokuryu’. Mingling together on the arch, these would create a spectacular bicolour effect, with their staggered blooming times extending the season of interest.
While the Dormancy refers to a period of inactivity in plants, during which they slow down or stop their growth, conserving energy and resources. This is a natural process that helps them survive harsh conditions, such as winter or drought. Dormancy in seeds is a mechanism that prevents them germinating until environmental conditions are favourable for growth.
A bud is a small, undeveloped shoot that contains the potential for new growth. Buds are typically found on stems, where they can be apical (found at the tip) or axillary (found between leaf axils) and may develop into leaves, shoots or flowers.
Saving the blooms
A run of late frosts over the last few years meant that ‘Kokuryu’ had not previously bloomed on the Wisteria Walk; the limelight dominated by the pale ‘Kimono’. However, for the very first time and thanks to true dedication from the horticultural team, this is the spring when we can finally enjoy the breathtaking two-tone display in all its glory.
By early April, the elusive ‘Kokuryu’ was covered in buds and with only a few frosty nights standing between them and an incandescent display, Matt and his team decided to pull out all the stops to protect the blooms.
Traditionally, when orchards and vineyards need to be protected from late frosts, sprinklers are left running overnight to constantly douse the buds in running water, or paraffin-based vineyard candles are lit. Uncomfortable with the environmental costs of these traditional methods, or with using any intervention for more than a couple of exceptional nights, Matt and his team decided, for two nights only, to improvise.
Surplus wood produced from tree surgery around the garden was gathered, and nine fire pits laid out along the length of the Wisteria Walk. Come nightfall, these were lit and dedicated horticulturists stayed in attendance throughout the night, taking shifts to stoke the flames.
The morning after the second frosty night, the team gingerly inspected the buds. Within about 5-6 hours, frost-damaged buds start to lose their pressure and go limp. But these buds appeared in fine fettle, and by a couple of days later, it was clear to see that they had survived unscathed and were continuing to grow.
What can we expect to see?
By April the whole arch was bursting with buds, ripe with promise for 2-3 weeks of really amazing display. By mid-May the wisteria was in full bloom, providing not just a stunning visual spectacle, but also a giddy perfume which is unmissable.
“The idea with the design is that the purple is early into flower, so the purple kicks off, the whole things lights up purple, and then the white follows after, and it finishes on white. At that crossover point, which we’ve never seen but will hopefully see this year, we have a crossover of purple and white, giving a two-tone effect,” says Matt.
‘Kokuryu’ burst into bloom in early May, and within a couple of weeks was joined by the paler ‘Kimono’, which takes the display through to the end of May.
In addition to ‘Kokuryu’ and ‘Kimono’, 16 other wisteria cultivars have been between the topiary alongside the Walk, providing a diverse display in a range of pinks, purples, blues and whites.
Planting for the future
Wisley is known for its magnificent collection of wisterias, expected to burst into glorious bloom all over the garden in April and May. The tree-climbing wisterias scaling 80ft-tall oaks in the Oakwood are thought to be unique in the UK, while compact freestanding standards showcase how wisterias can be grown even in a small open space.
To add another immersive dimension to the collection, Wisley’s Wisteria Walk was created in 2018. At 75m long, it’s an impressive spectacle, and one of very few like it in the UK.
Planting a wisteria is a long-term investment. As Wisley’s Garden Manager Peter Jones puts it, “you plant wisterias for 100 years”. It is hoped that the Wisteria Walk will be a landscape feature that lasts well into the future, and it is hoped that ‘Kokuryu’ is a cultivar that will only become more successful in a warming climate.
Wisteria is also a valuably climate-resilient plant. During last summer’s extreme heat and drought, Wisley’s wisterias suffered no drought stress at all. In fact, the heat promoted unusually good wood ripening and A bud is a small, undeveloped shoot that contains the potential for new growth. Buds are typically found on stems, where they can be apical (found at the tip) or axillary (found between leaf axils) and may develop into leaves, shoots or flowers.
As more and more gardeners reconsider what they can grow that will thrive in a changing climate, wisteria surely deserves a place on the list. Visit Wisley this late April or early May to see the Wisteria Walk as never before, and gather all the inspiration you need to choose your perfect cultivar from the huge range on display around the garden.