Each year, we run a public competition inviting people across the UK to help us find our Threatened Plant of the Year. These are plants that are no longer widely available from commercial sellers, so at risk of disappearing. Previous winners have included a rare Camellia, growing in a back garden in Edinburgh, a Peony bred by the renowned nursery Kelways, and a dwarf Clematis montana, selected from a plant collected in China over 100 years ago.
The 2025 shortlisted entries are now confirmed
Read the 2025 shortlisted entries below. These plants or images will be on display at RHS Hampton Court Palace Garden Festival 2025. The judges' winner will be announced on Monday 30 June 2025.
A public vote will be open from Monday 30 June until Sunday 6th July. The entry form will be live here during these dates. The winner will be announced on Monday 7th July.
The entry criteria are: Do you have an unusual, rare or special cultivar that is not currently available commercially? It must be a named cultivar that has been grown or sold in the UK or Ireland prior to 2015.
The 2025 Shortlist:
Aeonium 'Pen-du'
Aeonium 'Pen-du' was bred by Claire Batten of Penberth Plants in 2009. Aeoniums at that time had limited popularity being mainly grown by enthusiasts and sadly it faded from cultivation.
By chance, our entrant was contacted by an enthusiast who had bought a plant years before but could find no written information about it. The breeder confirmed its origins, but unfortunately, they had ceased its cultivation and had no stock left.
Luckily, our entrant got in touch with the location where their contact sourced their plant in 2013 and were kindly offered cuttings, which have been nurtured to bring this unique cultivar back to life!
Agapanthus inapertus subsp. pendulus 'All Gold'
This Agapanthus, notes the entrant, is the only truly yellow leaved form of Agapanthus, as the leaves remain bright yellow throughout spring, summer and into autumn.
They have grown this unique plant for 10 years having bought it from Pine Cottage Plants where Dick Fulcher had discovered it growing as a sport from 'Graskop' and noted it as particularly striking with a dark blue flower and a very gold leaf.
Camellia japonica 'Baronne Leguay'
Listed in van Houtte’s catalogue of 1873-74 as introduced by Mons. Cachet of Angers, (France) whose nursery was described as 'Camellia nursery, par excellence, of Europe' in Johnson & Hogg's October 1861 edition of ‘The Journal of Horticulture, Country Gardener & Country Gentlemen’. His great skill was much admired, evident in the claim that nothing could be seen to equal such exceptional quality of plants.’ Though unconfirmed, naming suggests being for the wife of Albert-Léon Le Guay."
Considered by our entrant to be a very special cultivar that has been part of the Worth Park estate ever since the circa 1887 construction of its unique and beautiful Camellia corridor.
The flower itself is a marvel to look at with pink petals with light white strip in the middle of each one.
Delphinium 'Alice Artindale'
A wonderful novelty at the time of its introduction, Delphinium ‘Alice Artindale’ is a double flowered rose-bud delphinium with an unusual layer of sepals, rarely seen today.
Our participant has nurtured this beauty ever since a plant fair customer prompted them to identify it over 15 years ago. Although it tends to resist producing cuttings and often experiences growth setbacks, this tall delphinium with its striking blue flowers accented by a pink hue is truly a unique find.
When planted in the ground and left undisturbed, it thrives beautifully. Originally registered by W. Artindale in Sheffield in 1936, it earned an Award of Merit that same year for exhibition and again in 1945 for its garden appeal.
Narcissus 'Fletching'
Narcissus 'Fletching' was registered as a cultivar by Sussex Breeder Noel Burr in 1998 as a cross between N. 'Broomhill and N. 'Canisp'. Many of Noel’s daffodils were named for places in and around East Sussex.
Our entrant having obtained this plant from a bulb grower in 2018, is dedicated to ensuring this lovely white daffodil presence in gardens continues.
Noel Burr had begun his daffodil journey in 1968 and went on to become a successful amateur exhibitor, prior to his death in 2017, Noel registered 58 cultivars. Only 23 of these are held in the dispersed National Plant Collection.
Penstemon 'Ridgeway Red'
Our entrant sings the virtues of Penstemon 'Ridgeway Red' stating that it stands out from the crowd for being more robust and hardier than most, having survived a terrible winter in 2022/23 when very few plants in the ground emerged unscathed.
It has striking flowers that last a long time and it is easy to propagate, what is not to love about this one!
Little is known about its history before 1993 when it was brought to the attention of the Specialist Plant Unit at Pershore College by one of its volunteers, Vera Memberson. Thanks to Vera this lovely rose coloured penstemon continues to be cultivated, though it could certainly use more attention!
Primula 'Julius Caesar'
Primula 'Julius Caesar' was previously thought to be lost. Once highlighted by the eminent botanist E. Charles Nelson as 'likely extinct', it was rediscovered in the 1990s through a connection with the family of the breeder Winifred Wynne of Avoca, Co. Wicklow.
Winifred was an avid primula enthusiast and breeder and was the middle of three sisters famous for their distinctly coloured woven fabrics produced at the Avoca Mill which they ran for ten years before purchasing the business in 1937.
An early flowering primrose with lightly bronzed leaves and beautiful claret flowers that deepen in colour as they age, it has a yellow eye that is tipped with white. Our entrant states we are fortunate to have 'Julius Caesar' to remember her by..
Rosa ‘Eden’ ('Peace' × 'Signora' 1953)
Rosa ‘Eden Rose’
Rosa ‘Eden Rose’ was bought by our entrant from Gregory’s rose growers of Nottingham in the mid-1950s.
It has proved itself a reliable grower having been moved around the garden a few times and never having shown any signs of disease.
It is a super deep pink with a rose-pink reverse. The fragrance has been intriguingly described as having hints of parsley, apple, clove & lemon.
Very full cupped bloom form hybrid tea that blooms in flushes throughout the season.
Rosa ‘Lorenzo Pahissa’
Rosa ‘Lorenzo Pahissa’ has been grown and conserved by three generations of the same family, the original cutting is believed to have been sent from the British Embassy in Madrid.
Our entrant describes it as a vigorous and healthy hybrid tea with fierce thorns. The buds are light pink but as the flower matures it becomes more apricot at the base of the petals with lighter champagne-coloured edges. It will flower from June to November and even into January if the weather is kind!
Bred by Lorenzo Pahissa it was named after his death in 1941, and won a Gold medal at Bagatelle, Paris that same year.
Salvia microphylla ‘Rodbaston Red’
Salvia microphylla ‘Rodbaston Red’ is described by our entrant as being special as it has great vigour, is easy to grow, and is very floriferous with a long flowering season from May through until frost. They say the foliage is attractive and delightfully fragrant and that it is loved by bumblebees, the short-tongued ones love to pinch the nectar from the side of the flower!
Named in 2005 for Rodbaston College after discovered as being incorrectly labelled as ‘Kew Red’ during a Salvia Study Day James Compton suggested ‘Rodbaston Red’ as an alternative.
It is a favourite amongst Plant Heritage Plant Guardians receiving compliments from all who grow it, whilst is it not commercially available it is shared annually through our Plant Exchange.
Tetrapanax papyrifer 'Di Sue Shan'
Tetrapanax papyrifer 'Di Sue Shan' is a lesser-known cultivar, often overshadowed by 'Rex', according to our contributor, who obtained their plant from The Bishop's Garden in Norwich.
They describe this plant as being much bigger, more upright and faster growing and that it is extra special in that it matures quicker which indicates that it is hardier from a younger age. Our entrant is emphatic that this lovely cultivar deserves to be known more widely.
The original plant material came from a collection by Crûg Farm Plants in 2007 from Dasyueshan, Taiwan and was named in honour of Diane Doughty, a valued helper at the nursery and nursery partner Sue Wynn-Jones.
Rosa 'Silver Lining'
Tradescantia ‘Danielle’
Discovering Tradescantia ‘Danielle’ illustrates the generosity between gardeners. Having seemingly disappeared from offer in UK nurseries since 2016, our entrant contacted Elizabeth MacGregor Nursery, Kirkcudbright, to ask about finding this rare and very special cultivar.
They were over the moon when in the following spring they received an unexpected gift of this plant through the post.
Our contributor say that what makes this plant so striking is the size of the flowers on compact foliage, with perfectly white petals and stamens and filament hairs topped with yellow anthers, it is one of the best white forms.
Entry requirements for the Threatened Plant Competition
- The entry criteria: Do you have an unusual, rare or special cultivar that is not currently available commercially? It must be a named cultivar that has been grown or sold in the UK or Ireland prior to 2015
- Research your plant: Start by checking the RHS Plant Finder - if 2 or less nurseries offer the plant for sale your plant may be be eligible. Click here for some ideas on researching your plant and click here for more online plant research resources
- Who could enter: Anyone (you do not have to be a Plant Heritage member) can enter up to 5 different cultivars. Please complete the entry form below
- Closing date: Wed 30 April 2025
- Shortlisted notifications: Plants are researched by our conservation team. Successful shortlisted entries will be notified by Tue 13th May. Entries are now closed and we will publish the 12 shortlisted entries by 20th June 2025.
- Competition time: The 12 shortlisted plants (or images of them) will be on display at RHS Hampton Court Palace Garden Festival 1-6 July 2025 . Our expert judging team will announce a winner on the 30 June 2025 at our press day event at the show. Everyone whose plant has been shortlisted is invited to attend. During the show week there will be a 'public choice' vote, which is announced on Monday 7th July 2025. The judges' winner receives an engraved vase, a special label and winners' certificate.
- Read about the 2024 entries here - the judges' winner, public choice winner and shortlisted entries