UK Edition
From shrubs to sweet peas – your ultimate guide to the winning plants of Chelsea Flower Show
Judges are certainly swayed by their own specialist interests, but who made this year's cut?
The Royal Horticultural Society’s Plant of the Year competition is the gardening equivalent of a parliamentary vote. As thousands of visitors feast on the floral extravaganza in the Great Pavilion, 100 or so top horticulturalists, mainly specialists who judge or trial plants for the RHS, gather to vote for their favourite new plant. Hands are raised and counted before a (hopefully) worthy winner is announced. Judges are definitely swayed by their own specialist interests, so the Woody Plant Committee will inevitably veer towards a shrub (five have won since the competition began in 2010). The Tender Plant Committee will always pick the half-hardies, and the fruit specialists will rave about anything that produces an edible mouthful.
And the winner is…
Yes, it’s a shrub! A collaboration between Suttons and Hillier, Cercis canadensis ‘Eternal Flame’, claimed top honours and it looked decidedly handsome on the day, with deep red heart-shaped foliage morphing into shades of autumnal gold and orange. It was raised by North Carolina State University’s breeding programme and introduced by Hillier nurseries at this year’s BBC Gardeners’ World Spring Fair. This very hardy American redbud matures to a 13ft roundel and it will need a bright position and good drainage. ‘Eternal Flame’ will also produce bright pink flowers just before the foliage appears in spring.
Pipped at the post
In second place was Allium ‘Lavender Bubbles’ (entered by The Sun newspaper) but it will be the real winner with gardeners because it produces its deep purple orbs of flower in August (rather than in spring, like most other alliums).
At 2ft high, this rhizomatous allium is perennial and the grey foliage has an attractive twist, so, given a sunny position, it will light up the dog days of August. It came out of a breeding programme at Walters Gardens in Michigan in the United States, so it’s terrifically hardy, and many of my gardening friends are already raving about it. It certainly got my vote.
Bronze beauty
Third place was hotly contested, but was eventually claimed by a succulent – allow me to introduce the beautiful intergeneric hybrid x Semponium ‘Sienna’, the world’s first official cross between two genera, Sempervivum and Aeonium. These fleshy plants are riding high in the popularity stakes as they’re adored by gardeners and houseplant enthusiasts alike.
Semponium ‘Sienna’, was raised and entered by Daniel Michael of Surreal Succulents of Cornwall. The cross involved a hardy sempervivum and an architectural aeonium and the result is a pyramidal plant with fleshy rosettes consisting of a green middle surrounded by darker outer leaves.
It’s hardier than most aeoniums, due to its sempervivum blood, although it will still need winter cover away from severe frost and winter wet. Incidentally, Surreal Succulents also has one of the best exhibits in the Great Pavilion.
One that got away
A pink form of the Balkan sage, Salvia nemorosa ‘Caradonna Pink Inspiration’ was withdrawn just before the judging. It was spotted by John Tuite of West Acre Gardens, near King’s Lynn in Norfolk, amid a clump of dark blue ‘Caradonna’.
‘Pink Inspiration’ has inherited the same dark, upright stems and floriferous habit; the combination of deep pink flowers, sage-green foliage and dark stems make this a winner for a sunny position. It’s a fabulous plant, if a little more compact than the original at 20in. It will be everywhere next year, so don’t miss it.
Best of the rest
One great plant failed to win any plaudits: Limonium gmelinii Dazzle Rocks. However, cut-flower enthusiasts (and pollinators) will appreciate this shorter, multi-stemmed sea lavender raised by Peter van Steijn, a Dutch plant breeder. He spent 10 years selecting from wild-collected seeds gathered in Hungary. It’s very hardy, very drought-tolerant and it produces neat evergreen foliage.
Salvia
Middleton Nurseries, a salvia specialist that sells roughly 250 types via mail order, is exhibiting in the Great Pavilion. This third-generation nursery from Sutton Coldfield entered three Belgian-bred Salvia microphylla cultivars.
These shrubby, compact salvias are hardy enough to be left in the garden, once established, and they flower until autumn turns to winter. ‘Delice Aquamarine’ is a grey-blue and ‘Delice Gold and Wine’ is a combination of deep pink and ripe peach.
Kale
The American-bred kale ‘Rainbow Candy Crush’, which took 10 years to select and name, is edible and decorative. It’s a serious bit of plant breeding from the “crossover project” undertaken by horticulturalists in Pennsylvania. They’ve taken the vivid pinks and reds found in some traditional kales, and added in edible brassicas to produce a sweetly flavoured, colourful kale high in antioxidants and anthocyanins.
Jacaranda
It took 10 years for Japanese breeder Kiyoshi Sakai, now in his 80s, to produce a dwarf jacaranda tree with ferny foliage and blue flowers. ‘Bonsai Blue’ is not fully hardy, but it’s small enough to be grown in a pot and moved somewhere frost-free for winter.
Verbena
National treasure Peter Seabrook has been The Sun newspaper’s gardening correspondent for 44 years. Behind every great man there’s a great woman, in this case, Peter’s late wife Margaret. In later years she suffered from dementia, so when Peter’s Verbena ‘Seabrook’s Lavender’ produced a pink flowering sport at Robin and Christine Grant’s Isle of Wight nursery, it was an obvious step to christen it ‘Margaret’s Memory’.
Sweet pea
A New Zealand-bred sweet pea, Lathyrus x hammettii ‘Three Times As Sweet’ was raised by Charles Valin for Thompson & Morgan. This fragrant grandiflora is the first tricolour, with lavender-blue, burgundy and white flowers.
Camellia
There’s also a breakthrough summer-flowering camellia, ‘1001 Summer Nights Jasmine’, with masses of single red flowers from May through to October. It was bred in China by camellia enthusiasts Gao Jiyin, Zhao Qiangmin and Liu Xinkai and is the first commercially available summer-blooming camellia. An interspecific cross between Camellia azalea and C. reticulata, it will need ericaceous compost.
Dianthus
Whetman Garden Plants, Devon-based breeders of dianthus, are putting the fragrance back into their newly bred repeat-flowering pinks, and Berry Blush is their offering for 2021. Fimbriated petals in shades of pink surround a blood-red centre, and these modern pinks, hybridised by the French-born plant breeder Laetitia Moucheboeuf, flower on and on.
Plants of the Year
