Dahlias blaze into colour just as other flowers are going over.
Image source: Shutterstock

After weeks of hot summer days, the grass is brown and withered, the summer raspberries have shrivelled into dessicated husks and the roses have gone over, but my dahlias are only just beginning. We’ve had the first brazenly crimson flower on ‘Con Amore’.

I’ve just started reading the sumptuous monograph ‘Dahlias’ by Naomi Slade, published earlier this month, and now I’m impatient to convert my dahlia dreaming into reality. I came to dahlias quite late in the day after picking up a few tubers of the charismatic Dahlia ‘Firepot’ at the school fete and I’ve been hooked ever since. They’re such a versatile flower – working equally well in mixed borders, containers or as bedding plants. Last year I also grew dahlias in the vegetable patch, and used the blooms for cut flowers.

Cut flowers

‘Café au lait’ is a favourite for cut flower arrangements.
Image source: Nic Wilson

My favourites include the sophisticated duo ‘Henriette’ and ‘Café au Lait’. ‘Henriette’ is a semi-cactus washed with apricot tones and ‘Café au Lait’, a double decorative with a soft pink blush which Naomi Slade describes as ‘rich as a cream liqueur on ice’.

Their elegant flowers last well in arrangements – either as an off-white display or mixed with the deep burgundy shades of ‘Thomas A. Edison’ and ‘Downham Royal’. These darker dahlias also create fiery contrasts with the neon punctuation of ‘New Baby’ and burnished orange of ‘David Howard’. Growing flowers in these three tonal ranges allows me to create harmony and contrast in different rooms as the mood takes me.

Borders

‘Bishop of Llandaff’ brings a striking scarlet accent to your borders.
Image source: Thompson & Morgan

Dahlias bring extra colour to late summer borders and their foliage is a valuable addition even before the flowers, especially with the rich chocolate purples and greens of the Bishop Series. If I could only grow one dahlia, it would be ‘Bishop of Canterbury’ – it has the same dark foliage as the more popular ‘Bishop of Llandaff’, but with luscious magenta-pink flowers.

For a more elegant border dahlia, ‘Twynings After Eight’ retains the dark chocolate foliage alongside single white flowers with a saturated yellow central boss.

Containers and bedding

The smaller dahlia ‘Scura’ is ideal for containers.
Image source: Nic Wilson

Smaller dahlias are well suited to container growing and bedding displays. For punchy colour try ‘Scura’, one of the Mini Bishop Group, which has deep orange petals with apricot undertones, or ‘Happy Single Date’ with its cheerful tangerine flowers flushed with red at the centre.

‘Fire and Ice’ creates its own contrast with vibrant red and white striped flowers on sturdy plants and you can’t beat the semi-double flowers of ‘Sunny Reggae’ in all shades from buttery apricot through to vivid red to liven up any area of the garden.

Dahlia care

Dahlia ‘Happy single date’ is easily accessible to bees in a wildlife-friendly garden.
Image source: Nic Wilson

Whether you’re planting dahlia tubers in containers from late winter/early spring or in the ground after the last frosts, they need little attention apart from feeding and comprehensive defense against the gastropodic arts. I begin all my tubers in containers – this year’s spring rain (hard to remember now) attracted the slugs and snails who wreaked havoc on the emerging shoots. My normal barriers of copper tape and wool pellets proved futile and I had to resort to placing all the dahlias on the patio table with copper tape circling each leg.

The plants need liquid feeding throughout the growing season – a high nitrogen feed initially, followed by a high potassium feed when they start flowering. Once autumn frosts begin in earnest, lift the tubers, cut back the stems and dry upside down before storing in sand or compost in a frost-free place. In milder areas, tubers can be left in the ground and well mulched with compost, manure or straw.  Most years this works for me, with occasional losses in particularly wet, cold winters.

Anticipation

‘Thomas Edison’ is a beautiful addition to cut flower displays.
Image source: Nic Wilson

In the next few weeks I’ll be waiting impatiently for ‘Karma Choc’ and ‘Daisy Duke’ to flower, both new for me this year. And I’m already planning my dahlia selection for 2019. How can I resist just a few tubers of ‘Sierra Glow’ – described by Naomi Slade as the “most gorgeous bronze, brushed with coppery pink and with hints of dusty rose”? I suspect, with tens of thousands of cultivars available, I’ll be indulging in dahlia dreaming for many years to come.

If Nic’s article inspired you, learn how to grow & care for your own dahlias using our dahlia hub page – T&M’s one stop shop for everything you need to know about growing dahlias.

Nic Wilson

Nic Wilson is a writer, garden designer and Garden Media Guilds Awards nominee (Beth Chatto Environmental Award, 2019). She enjoys growing flowers and unusual fruit, vegetables and herbs, and loves to encourage nature into the garden. She blogs at www.dogwooddays.net, and Guardian Country Diarist based in North Hertfordshire.

She works for BBC Gardeners’ World Magazine and her writing has featured in anthologies, journals and magazines including The English Garden, The Garden (RHS Magazine), BBC Wildlife Magazine and the John Clare Society Journal.