UK on Cusp of an Almighty Explosion of Summer Colour
by RHS
July 26, 2020

UK gardens and green spaces are on the verge of a unique explosion of summer colour as the peak of two flowering seasons combine to create the most dramatic spectacle seen in years, says the UK’s gardening charity, but the best of it could be over in days.

The Royal Horticultural Society (RHS) reports that this year’s weather has provided the optimum growing conditions* for summer flowering. The warm, wet winter followed by the sunniest May on record and then a bout of rain in June has produced an exceptional crop of summer blooms.

Stronger, bigger buds and more prolific flowering has created abundant displays of early blooms such as lilies, rhododendrons, irises, roses and hydrangeas, and mid-summer flowers such as verbena, rudbeckia, heleniums and geraniums are now coming into their own.

The apex of this floral extravaganza may happen this weekend and at the four RHS Gardens the show has already begun but the seasonal overlap could pass by quickly as early summer flowers are likely to start going over next week.

Curator Paul Cook says that thanks to steady temperatures, no drought and enough rain RHS Harlow Carr in Harrogate is currently producing prolific displays of a wide variety of summer flowers which ‘have never looked so good’.

Paul says; “Pink water lilies, white rhododendrons and pink, red and white roses are still going strong and at the same time there are masses of electric blue geraniums, yellow primulas and purple irises coming into flower. We also have 42 varieties of rudbeckia blooming right now creating a sea of vibrant reds, yellows and oranges.”

At RHS Rosemoor, in Devon, Curator Jon Webster says fiery displays of red hot pokers, rudbeckia, dahlias and goldenrod are springing to life in the Hot Garden while whites, blues, pinks and purples bring a sense of calm in the Cool Garden. The two rose gardens are still brimming with colour and scent.

RHS Garden Wisley in Surrey is still teeming with big, blousy hydrangeas and the lavender is looking its best. Garden Manager Peter Jones, says: “There is so much to see. The prairie style Glasshouse Borders are singing with more flowers than I’ve seen in years with beautiful reds, pinks, purples and blues and in the South African meadow we are seeing the most brilliant spreads of kniphofia the red hot poker.”

Rudbeckia, lavender and agapanthus are having an unusually abundant year at RHS Hyde Hall in Essex and a 3 metre tall Dasylirion wheeleri is flourishing in recent conditions providing a rare treat for visitors. The popular Floral Fantasia display has also returned this year and features thousands of colourful summer-flowering plants.

Ian Le Gros, Head of Hyde Hall, says “Although no season is ever the same, ideal levels of sunlight, warm evenings and a spot of rain has meant we have an unusually good year for flowering.”

RHS Partner Gardens are also reporting outstanding spreads of colour. The Bishop’s Palace Garden in Somerset is awash with daylilies including ‘Chicago Sunrise’, blue salvias and their Bishop series dahlia collection is thriving. Garden Manager James Cross says; “Everything has come together to produce the best summer colour I have ever seen.”

*Guy Barter, RHS Chief Horticulturalist, explains; “It all started at the end of last year with good levels of light, enough rain and warm temperatures to produce strong plants coming into the year and these dreamy conditions continued when our sleeping perennials awoke to dry weather and moist soil.

“A lack of frost and the light, warm start to the year meant growth was really good helping produce big bulbs and lots of them. The sunniest May on record was followed by an unusually wet start to the summer, with England seeing 43% more rainfall last month than the June average, according to the Met Office.

“This combination of weather phenomena saw the sunshine bring early summer flowers into bloom earlier, while the welcome extra rain has helped stretch their season over a longer period. And all this combined has created the best crop of herbaceous plants seen in years.

“Our work is done in the garden so happily all that’s left to do is enjoy the summer spreads. The outstanding blast of colour that’s about to hit will bring even greater enjoyment than normal but you’ll need to be quick to catch its full glory.”

About the RHS

The Royal Horticultural Society, the world’s leading gardening charity, was founded in 1804 by Sir Joseph Banks and John Wedgwood. Our vision is to enrich everyone’s life through plants, and make the UK a greener and more beautiful place. This aspiration underpins all that we do, from inspirational gardens and shows, through our scientific research, to our education and community programmes such as Campaign for School Gardening and Britain in Bloom. We produce key publications, hold a world-class collection of horticultural books and botanical art, and sell the very best plants and gardening gifts.

The RHS is fundraising £40m to transform our gardens, outreach and education facilities, which includes redeveloping our flagship RHS Garden Wisley and opening a new garden, RHS Garden Bridgewater, in 2020. We are solely funded by our members, visitors and supporters. For more information visit

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