Make your garden last longer with dahlias
Dahlias are one of the most valuable plants if you want a long flowering season, but they have been unfashionable until recently.
A typical dahlia border used to look like a fruit salad. There were random mixes of brightly coloured dahlias in white, yellow, red and pink. And they stood in serried rows without any under-planting.
Context is everything in gardens. So now many gardeners use dahlias differently. You can see new, interesting directions in foliage. And we partner dahlias with a wide range of other flowers to create dramatic effects.
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‘Few plants can rival dahlias if you want a long season in your garden,’ says Steven Edney, head gardener at The Salutation garden in Sandwich. ‘They flower from two to five months at a time, depending on your climate.’
Steven has dahlias in his blood. His family bred dahlias. He has been part of the RHS dahlia trials at Wisley, and he has now created a beautiful dahlia garden at The Salutation.
The Salutation was designed by Lutyens. Steven joined eleven years ago to restore the Grade 2 Listed garden. At that point, there was a mound of rubbish and rubble instead of a vegetable patch. It is now a delightful mix of dahlias and vegetables.
Colour theme your dahlia border
Dahlias used to be planted alone in beds, in a riot of contrasting colours. There is a traditional dahlia bed at The Salutation, where the colours move through the colour wheel. Reds and pinks are followed by purple, yellow and white. Stripes and multi-coloured dahlias are at the end.
There is a trial bed, where Steven subjects his dahlia types to the kind of treatment they would get in an ordinary middle-sized garden.
‘I don’t water them, and I only feed them with a manure mulch and some blood, fish and bone,’ he says. ‘That’s what most domestic gardeners would do, and it’s important to see how they survive in non-professional gardens before we sell them to the public.’
Even so, the dahlia bed is colour-themed, with dark reds, pinks, peaches, yellows and moving harmoniously through the colour spectrum.
Think about the foliage as well as the flowers
I love the use of foliage and colour in The Salutation’s dahlias.
Steven is always growing and trialling new dahlia seedlings and crosses. He sees how the public responds to the new varieties. Dahlias are tested for a couple of years to make sure they come back true and are reasonably hardy.
Use dahlias in exotic gardens
Dahlias were originally imported from Mexico, so they can be considered ‘exotics’. With bright colours and sharp sculptural shapes, dahlia flowers are an ideal choice for exotic gardens. The Salutation has an Exotic garden just by the entrance. Steven and his team are planning to expand it next year.
‘I’m very influenced by Gertrude Jekyll,’ says Steven. ‘She combined exotic plants like ricinus with dahlias in her own garden.’
Steven’s own garden, created with his partner, Lou Rawle, is an exotic garden, also featured on this blog.
Combine dahlias with vegetables
As well as extending the flowering season in the garden, dahlias last a long time in the vase. They are cut-and-come-again flowers, which means that the more you cut them, the more flowers you’ll get.
Dahlias were, in fact, originally imported as food. The tubers are like potatoes, apparently. Personally, I can’t quite bring myself to try them. If, however, you dig your dahlias up at the end of the season, you could roast them.
At the Salutation, the dahlias in the veg beds are partnered with kale, chard, pernilla for leaf contrast.
New dahlia trends in pots
Dahlias with sculpture
A simple recipe for an eight-month border
This is a simple border plan which can be in flower from February to October, depending your climate. There are bulbs in the border at the beginning of the year, with bergenias in the front. Then irises and peonies take over, followed by dahlias. The orange dahlia is City of Alkaar.
Easy ways to deal with dahlia problems
I’ve found dahlias very easy to grow, but they do have a few problems. They get eaten by slugs. The flowers can be nibbled by earwigs. And there’s also the thought of digging them up and storing them over winter. But all three of these problems are relatively easy to deal with.
Steven recommends using Growing Success, an organic-approved slug remedy and also a wool-based mulch which slugs don’t like crawling over. Use these from February onwards. Once the plants are big enough in June and July, slugs and snails won’t matter so much.
Steven gardens in a wildlife-friendly way. For example, to deter earwigs, he puts a mixture of molasses and boric acid in a flowerpot and puts it upside down on a stick. The earwigs crawl in and die, but they’re not poisonous to any other wildlife that eats them.
As for digging your dahlia tubers up in winter, Steven suggests you don’t dig them up. He has dahlias that have over-wintered in the ground for thirty years. He covers them with mulch to protect them from frost. Not all will survive, but a surprising number will. ‘Christopher Lloyd threw all his dahlias out at the end of every season,’ he says.
If your dahlias don’t survive the winter, buy new ones.
If I haven’t convinced you to try dahlias, do visit The Salutation. It’s changed dramatically since it was flooded in the surge tide of December 2013. Parts of the garden were completely washed away.
‘We didn’t have much of a budget to replace the garden, so I had to learn alot,’ says Steven. ‘And I had such support from the gardening community. The head gardener at Sissinghurst rang up and brought his whole team down for a day just to help. And lots of other people contributed plants or help, too. I’ve become a better gardener because of the experience. And the Salutation is now a better garden.’
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