Sheep garden blog: dealing with dahlias

Tiffany Daneff / 21 July 2014

Perfect weather for dahlias; and has anyone else been bugged by rose beetles?

It’s too hot! We are all wilting, even the dahlias are looking dog-eared. Or should that be slug-eared?

I love dahlias. They are one of the great joys of gardening but when I left London I left all my dahlias behind. I had a gigantic Black Cat that produced glorious velvety dark blooms so big that one was enough to make an impact and yet it would produce a mass of them right up until November. I also adored the orange Jescot Julie but she had become exhausted and was producing far fewer flowers. Before we moved, I had bought some new Karma dahlias but they were left behind in the chaos of moving.  

When we moved in here I longed for the chance to start afresh with new varieties. There is nothing more delightful than leafing through photographs of brilliantly coloured dahlias and deciding which to order. (I recommend Andy Vernon’s The Plant Lover’s Guide to Dahlias, Timber Press, £17.99.)  The main downside is that there are far too many contenders and you seriously have to stop yourself over ordering.  

It’s also so easy to forget how much space they take up and, again, are tempted into ordering far too many.  There’s a nice video of Andy admiring the dahlias at Kelmarsh on the intoGardens' YouTube channel - click here to open the page in a new window.

I chose six tall ones, which were supposed to be going into one of the veg plots to make a cutting garden but then I used all the space with veg (cavolo nero, hero veg - see right) so this year they are making up the gaps in the young borders. I will need to dig up the tubers and overwinter them (which I have never tried as in London they were fine left in the ground with a protective layer of mulch on top).  When it comes round to winter these two videos on intoGardens' YouTube channel might be useful:

Originally the plan was that I would cut sturdy hazel lengths to support them but, in the end, I found some good stakes in a small agricultural store so I bought six of those instead.  

I also bought two shorter D. Roxy for pots. These dwarf dahlias have a lovely, deep-green leaf and stem with brilliant pinky-magenta single flowers and a smart dark eye. (20ins)

Into the borders have gone one each of these:

  • D. Hillcrest Royal a favourite of Christopher Lloyd, big blousy cactus dahlia in a deep, violet-tinged carmine, 47ins
  • D. Karma Fuchsiana, zingy coral-orange dahlia – almost luminous, 36ins
  • D. Purple Haze, deep purply-pink anemone type (though variable) with dark leaves, 42 ins
  • D. Juliet - a new dahlia with large single flowers and contrasting dark leaves, 36ins
  • D. Happy Halloween - gorgeous, orange decorative, 43ins.  Just take a deep breath and ignore the ghastly name
  • D. Clare de Lune The prettiest, soft yellow collarette type – grow it with Verbena bonariensis, suggests Andy Vernon, 40ins

The tubers quickly sprouted once potted up but have been quite slow to get going now they are in the ground which I think is probably because it is so clay-ey here. I had taken care to put a lot of gravel at the base of the large, one-foot-square planting holes. I also gave them large dollops of compost and bonemeal on top of a heap of grit to help with drainage.  The stakes went in at the back of the planting hole and were banged in with a large hammer before the plants went in.  

I left pinching the tips out a bit late. The tip of the main shoot needs to be cut or pinched cleanly off down to the first pair of leaves.  

This makes the plant more bushy. Even more brutal: you must remove all extra stems leaving just five.  Any more than five and they will be weedy. By keeping the plant in check like this you will get strong stems (important to support the often heavy large flowers) and more blooms.

They are greedy plants so I am feeding them once a fortnight with liquid seaweed fertilizer and also giving them a good soak when it’s dry.

The snails and slugs have been a right nuisance and I’m afraid I have had to resort to old-fashioned pellets to save the plants' lives. Even now that they are beginning to get a move on, the pests are perfectly capable of shinning up to quite a height and leaving holes in the leaves.

Dahlia Roxy are already flowering but those in the borders are only just budding. But, with more of this fabulous tropical rain and sun, it won’t be long before they start putting out.

Ps Has anyone else been visited by squadrons of little black beetles on their roses?  And how best to deal with them?


Tiffany Daneff is also the editor of the award-winning intoGardens app - the world's first magazine app for gardens. Visit the appstore to download a free sample or go to the website for more information. Gardening has never looked better or been more exciting. Visit for more info. 

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