Variegated compositions of plants and flowers at Chelsea Flower Show
Popular Autumnal Flowers Likely to be on Display at RHS Chelsea Flower Show 2021

For the first time in history, the RHS Chelsea Flower Show 2021 will take place in September, allowing late flowering plants and autumnal grasses to take centre stage. Pumpkins and seed heads will no-doubt also feature heavily, replacing the fresh pastel colour palette that’s usually on offer in May.


To celebrate this change in schedule, we’ve spoken to gardening experts and analysed Instagram and Google data to determine which popular blooms are likely to feature heavily at the first autumnal RHS Chelsea Flower Show.


Calum Maddock, gardening expert at HomeHow, commented: “This year’s celebrated flower show will feature many unfamiliar sights, trends and shrubs as exhibitors look to overcome the challenges posed by the change in season. We’ll see a richer colour palette emerge, as burnt oranges, deep yellows and rich reds characterise late summer blooms. I’d also expect to see a lot of fruiting plants and ornamental grasses as these thrive at this time of year.”


1. Hydrangea

Hydrangeas are an incredibly popular flower, so it’s no surprise these late blooming flowers take the top spot for most Instagram tags with more than 3.4 million. Hydrangeas also take the top spot for the number of Google searches each month, with over 72,000 searches in the UK alone.


Gardening expert Calum Maddock of HomeHow, predicts they’ll feature heavily at this year’s show: “Hydrangeas have a brilliantly long flowering period and are available in a vast array of different colours, so it’s no surprise they frequently feature in Instagram posts.


They normally bloom until late summer/early autumn, despite not typically being seen as an autumnal plant. I expect they’ll feature at the flower show in abundance due to their extreme popularity. Visitors always engage with gardens that feature flowers they recognise, and hydrangeas are highly recognisable!”


Hydrangeas are easy to cultivate, thrive in almost any soil conditions and are incredibly diverse – giving them the nickname of “the perfect shrub”.


2. Dahlia

Dahlias provide colourful flowers that bloom from midsummer right through to autumn – when many other plants are past their best. This may account for the flowers’ popularity on Instagram, with over 1,700,000 tags. There are also over 39,000 monthly Google searches for Dahlias within the UK.


Gardening expert Calum Maddock, commented: “Most people think Dahlias are purely summer flowers, but they’re not. They can bloom anytime between June and early December. Different varieties of Dahlia offer a spectrum of stunning hues. They come in all shapes and sizes, from fun, ball-shaped flowers that stand proud atop their stems to those with layers of fanned petals. There are 42 species to choose from. Their diversity means they’re guaranteed to steal the show!” 


Designer Thomas Hoblyn has already confirmed that Dahlia Campanulata will be on display within The Boodles Secret Garden – a sanctuary garden he’ll be exhibiting at the show. 


3. Chrysanthemum

Chrysanthemums are members of the Asteraceae family and are closely related to Dahlias. They offer valuable, late flowers in September and October so it’s highly likely they’ll feature in many gardens at this year’s RHS Chelsea Flower Show.


They appear on Instagram over 694,000 times and receive over 52,000 Google searches each month.

Maddock says: “Orange, burgundy, and yellow hued Chrysanthemums offer an instant splash of Autumnal cosiness. They’re the perfect addition to any autumnal display as the leaves begin to fall and the gardens of Chelsea begin their retreat into winter.”


Chrysanthemums are hardy, can be grown in containers, can be kept indoors, are perfect for borders and are available in an incredible range of different colours, so their popularity is no surprise.


4. Camellia

Camellias are attractive evergreen shrubs that can bloom right through winter. In particular, the Sasanqua and Japonica varieties are good choices for autumn and winter blooms as they prefer cooler climates (they are usually hardy to -12°C). They produce stunning flowers in a range of reds, whites and pinks.


Although camellia flowers are bold and striking, they’re not the easiest to grow initially. Camellias will only thrive in ericaceous (acidic) soil in a spot that’s cool and away from direct sunlight.


Designers Tawatchai Sakdikul and Ploytabtim Suksang have confirmed that Camellia Japonica ‘bicolor’ flowers will appear in The Calm of Bangkok – a sanctuary garden they’ll be unveiling at the show.


5. Sedum

Sedums, also known as stonecrops, feature fleshy leaves and nectar-rich flowerheads that are loved by bees. There are many different varieties sedum, which makes them suitable for use in almost many garden, and may explain why they’re so popular.


Upright Sedum are easy to grow and provide a striking garden feature in late summer and early autumn, when flat, bright flowerheads bloom in many vivid colours. 


Sedum is also quickly becoming a popular indoor plant thanks to the Millennial and Gen Z houseplant trend. Sedums have been tagged over 580,000 times on Instagram, with many of the posts displaying indoor sedum varieties.


6. Salvia

Salvias are mainstays of many gardens – blooming from mid-summer to autumn. There are around 900 Salvia varieties that produce flowers of all colours, from electric blue to lemon yellow to vivid red.


Salvia flowers are tubular with a split lower petal. Foliage shapes and colours are also very varied. Many Salvia varieties are hardy and herbaceous – both sage and rosemary belong to the Salvia genus.


The diversity of flower colours and the length of flowering – May to November – make Salvia a real favourite with gardeners as well as with internet users. Salvias appear in over 414,000 posts on Instagram. The term ‘salvia’ is googled over 39,000 times per month within the UK.


7. Echinacea

Echinacea have grown in popularity in recent years, mainly thanks to the growing trend for prairie planting. Prairie planting focuses on the use of ornamental grasses combined with late-flowering perennials, to create a naturalistic look – a style that will no doubt feature at this year’s flower show.


Echinacea are easy to grow and produce pretty daisy-like flowers with a central cone; hence they’re commonly known as coneflowers. They flower all through the summer and well into autumn.


8. Aster

Asters are part of the Daisy family and flower mostly in late summer through to autumn, which gives them their common name of Michaelmas Daisy. Asters are ideal for growing in mixed borders and with ornamental grasses. They’re likely to feature heavily alongside Echinacea in prairie-style gardens at this year’s show.


Asters display vibrant autumn colours in shades of pink, purple, blue and white and bloom predictably and reliably. They’re also one of the last great feeding opportunities for bees, butterflies, and other pollinators, so their planting is to be encouraged.


9. Cyclamen

Cyclamens are a welcome sight in the colder months when so little else is in flower. Some cyclamen varieties flower from September to December, others from December to March.


Cyclamens are hardy, tuberous perennials that are ideal for naturalising under trees, on banks or in a shady border along with other early-flowering woodland plants such as snowdrops and primroses.


Cyclamens range in colour from pure white through all shades of pink, lilac and red. They also feature rounded or heart-shaped leaves that are dark green in colour with white marbling.


Their popularity as an easy to grow winter flower means they’re highly likely to feature in at least one show garden at this year’s RHS Chelsea Flower Show.


10. Alstroemeria

Alstroemerias are herbaceous perennials that flower in summer and last through to the first frosts of winter.


A great addition to borders and containers, Alstroemerias produce showy flowers in a wide range of colours, including white, yellow, red, orange and pink. Their petals often feature contrasting colour patterns and speckled throats.


Most Alstroemerias are hardy and easy to grow, blooming generously for many years, so their popularity is no surprise. Over 127,000 posts featuring Alstroemerias have appeared on Instagram.


Final Thoughts

Our luxury garden rooms are designed to be used all-year round as we use only the very best structural insulated panels within our builds. However, planting colourful autumnal and winter flowers within your garden, such as Hydrangeas, Sedum and Camellia, will make your outdoor living area much more inviting during the winter months. 


If you’d like more information on how we can incorporate a garden room into your autumnal garden, please contact us. We’d be happy to help!