Taste and generally how to avoid it - Dahlias

At a recent plant sale I had a number of dahlias in my display and an individual came up and went "ooh that's nice, what is it?", read the label "Oh a Dahlia!" and hurriedly put it back, looking round to see if anyone had noticed this lapse in taste.

Amongst gardeners of taste dahlias such as Bishop of Llandaff and species such as D merckii have been the only one's allowed root room. However they are creeping back into our gardens, aided and abetted by Christopher Lloyd and Fergus Garret at Great Dixter, Sarah Raven and many NT gardens who use them for late colour and interest. The bedding display in Bath Botanic Garden [to the right] makes a good splash of colour into late autumn - perhaps a little too formal but the plant combinations give some good ideas - the mix includes dahlias, cannas, Lobelia cardinalis and busy lizzies.

Why have these flowers of the exhibition show benches had such a hard time in the garden?

Margery Fish in her book, We Made a Garden, perhaps encapsulates the attitude that many have towards dahlias, the work they involve, their ungainliness, masculinity, and potentially flower bed unfriendliness

"When we first started gardening I was only allowed to watch [for future reference] the great ritual of planting dahlias. I think I was permitted to get barrowloads of manure and cans of water, but he [her husband Walter] would not trust me to do more..... [finally after Walter's death] I was reduced to two very ordinary red ones, a double and a single, and these I leave in the ground. They come up year after year and I am quite pleased to see them."

Christopher Lloyd is robust in defence - "Dahlias spell excitement and we can do with some of that in our lives."
He gives tips on cultivation and combining them successfully in the flower border in his book - Christopher Lloyd's Garden Flowers.

Originally from South America you can understand why dahlias are borderline hardy in many areas of the UK and why the recommendation is to lift the tubers and store over winter - however if you are a lazy gardener like me, and especially if your soil is fairly well drained, and you live more to the south - leave 'em in. If you lose them it's a good excuse to try some different one's.
The bed [to the right in mid Sept] is in my mother's garden, a less hectic combination than the exotic planting above. This is a fairly shady border with quite a few borderline hardy plants as well as gingers, agapanthus and dahlias that both she and I have bought over the years. The dahlias are topped up a bit but none are lifted, they are just left to get on with it.

Species dahlias such as D imperialis as pictured in Phillips & Rix blow all your dahlia conceptions out of the window! Growing up to 9m tall where happy, with masses of single pale pinky flowers, sadly only suitable for warmer climates and heated conservatories. D merckii a mexican native, is very good for the flower border, growing up to 2m with single light pink flowers. It is an airy plant with a delicate feel and can overwinter in the ground depending on the severity of the cold. D coccinea is another species to try with single variably orange-red flowers.

A number of species dahlia arrived in Europe in the 1700's, named apparently after Swede Andreas Dahl [why?], a pupil of Carl Linneaus. Hybridisation for showing started in the early 1800's. Today they come in many different shapes and sizes, some of which are not to my taste - favourites tend to be from amongst the spikey petalled cacti forms and oddities and singles. Dahlias come in most colours except blue, some extremely loud and shouty others with great richness.

To the left is Bishop of Llandaff, much used in hot themed plantings for the contrast of the dark foliage against the vibrant flowers. To the right is David Howard another dahlia where the orange fruit pastille flowers contrast with the dark foliage. I also like Bloodstone a small decorative which has very intense red flowers, especially effective in semi shade. I think Giraffe is fun with scruffy flowers in tawny bronze with darker flecking. I have also grown Mick's Peppermint a fairly bold semi-cactus, white flecked with red. I was disappointed with the two waterlilies that I tried last year. This year who knows?

Dahlias can be grown easily from seed, the BBC Gardener's World 2005 Trial gives some interesting pointers,
http://www.bbc.co.uk/gardening.

Suppliers also sell the tubers when they are dormant and young rooted cuttings in the Spring. The worst pests in my garden are slugs and snails, they can strip a nice juicy dahlia overnight. Dahlias are frost tender so should not be planted out until the danger of frost has passed. Dead heading is a must to keep the plants looking good and the flowers coming all season. For detailed cultural instructions visit the National Dahlia Society website below.

Go on, plant some dahlias this year and enjoy a fabulous display way into the autumn and they are brilliant as cut flowers too.

References:
Conservatory and Indoor Plants, Volume 2 [1997] - Roger Phillips and Martyn Rix
We Made a Garden [1956] - Margery Fish
Christopher Lloyd's Garden Flowers [2000]

Where to buy plants and seeds

The National Dahlia Collection - many of the entries have pictures to help you choose. Young rooted cuttings are sent out in April and May each year. Species available include D imperialis.

Plant World Seeds - for D coccinea palmerii and D merckii

Where to see

Great Dixter in Sussex - be prepared for a heady and exotic mix of colour and form in later summer!

National Dahlia Society Shows - whilst you may not warm to the staging you will see a wide selection on display.

RHS Wisley in Surrey trial fields - link to 2006 Award of Garden Merit winners

@Kari's garden 2007