Dahlias are the darlings of late summer and autumn, their blooms providing bursts of colour whether in pots or beds and borders. But some are better at showing off on patios, while others will nestle happily amid perennials and shrubs in a wider setting, or set off a zingy palette in a tropical garden.
Dahlia specialist Rob Evans, owner of Pheasant Acre Plants (pheasantacreplants.co.uk), a Chelsea Gold Medal-winning nursery, says: “Whatever dahlia you choose, they prefer full sun, being native to Mexico, and we now grow them in peat-free compost and find they do just as well.
“To keep them going through to the autumn, feed them every 10 days to two weeks with a high potash feed or a tomato feed and deadhead on a regular basis. At this time of year they need to be watered three times a day, depending on the size of the pot and the type of compost you are using.”
Where to grow dahlia and which dahlias to plant
So, which types suit particular settings?
Dahlias in containers
“I would go for ‘Melody Allegro’, a decorative salmon pink dahlia, and ‘Genova’, a miniature ball, which look good as standalone subjects in containers,” suggests Evans, who is set to exhibit at Malvern Plant and Garden Fair in September. “‘Mystic Illusion’ is another candidate, which has dark foliage and a bright yellow daisy-like flower. They all grow to around 3ft.”
“There’s a really spectacular decorative dahlia called ‘Miss Brandy’,” he continues. “The flowers, which are orange on the face and more of a red-orange on the back of the petals, are about five inches across.”
Award-winning garden designer and plantsman Andy McIndoe, who runs courses with Learning With Experts (learningwithexperts.com), agrees that the Mystic Series is very good in pots. “They are compact, generally shorter and have dark foliage; another big tick box. Anything with bronze leaf gives you an additional point of interest.”
McIndoe reckons “’Mystic Sparkler’ and ‘Mystic Wizard’ are good bets.”
Read more: How to grow dahlias in pots
Dahlias in a tropical setting
McIndoe recommends ‘Dahlia Karma Choc’, a deep red flower with very dark foliage as a great tropical border variety, and points out the widely available ‘Bishop of Llandaff’ would also look good in an exotic setting.
Evans adds: “We have a variety ideal for tropical settings called ‘Brown Sugar’, which bears deep brown-red flowers, which will be a great combination with canna lilies in full sun.”
Dahlias in borders
Good border choices include the salmon-apricot ‘Hillcrest Suffusion’, which will sit happily in the middle of a border, and ‘Tartan’, an eye-catching maroon and white medium decorative type which grows to around 4ft and may not need staking if you have other plants in the border which would hold it up, says Evans.
“Plant it with grasses such as miscanthus to show it off,” he advises. “And repeat plant groups of dahlias throughout a mixed border, which will continue flowering until the first frosts.”
Dahlias in a contemporary garden
“I’d just go for one or two of the giant dahlias to give it a pop of colour, such as ‘La Luna’, a lemon yellow type that grows to around 5ft and would need to be in the ground, not in a pot,” says Evans. “If you only have room for one pot, go for something like ‘Totally Tangerine’, which will go in most hard landscaping designs. Bees adore the anemone flowers and are continually in flower throughout the summer.”
Purples, whites and pinks go well together, so gather pots of the soft pink single-flowered ‘Teesbrooke Audrey’ with white waterlily types ‘Peace Pact’ and ‘Berner Oberland’, Evans suggests.
“Dahlias look great in borders planted with dark-leaved heucheras, ajugas and perennial phlox, which flowers early in the season,” he continues. “Crocosmia ‘Emily McKenzie’ can set off the palette. The flowers are bright orange with dark red centres, which brings out the colours of the dahlias and creates a sizzling display.”
“Dahlia ‘Jowey Joshua’, a yellow ball variety with a red overtone, will be beautiful with heleniums, rudbeckias, heliopsis and asters,” Evans adds.
Dahlias also look good planted with penstemons, McIndoe notes: “You have the contrast of flower forms. Verbena bonariensis and Dahlia ‘Bishop of Llandaff’ is a classic, which goes back to Vita Sackville-West at Sissinghurst.’”
Dahlias for cutting
So many dahlias are great for cutting that it’s difficult to make a choice, says McIndoe.
“A good long-term one is the very dark-flowered ‘Arabian Night’, which produces the most amazing cut flowers. I got so fed up with them in the border, I chucked them on the compost heap, where they bloomed magnificently.”
The Malvern Plant and Garden Fair takes place September 12-13. For details visit threecounties.co.uk/whats-on/malvern-plant-garden-fair.