Dahlias

The sweet-shop delights of ordering new dahlia tubers

Dahlia ‘Sam Hopkins’ in my border at the front of the house.

I have just ordered a whole load of new dahlia tubers as I think I’ve lost all my existing plants this winter. I usually dig up about half my tubers over winter as a safety net but last autumn I didn’t get round to it, thinking it was safe to leave them in as we’d been having such mild winters. A few weeks later in early December we had a week of very low temperatures, down to -8C, followed by many weeks of heavy rain. I think it’s the prolonged rain more than the freezing temperatures that causes them to rot, so I am kicking myself for letting my guard down and losing them all. But it does mean I can try some new varieties and it will prompt me to dig over the bed I usually grow them in to get rid of some overgrown euphorbias and shrubs that were starting to push out the dahlias.

I love dahlias for their mad, crazy diversity, for their bold colours and shapes, and for their ability to outlast most other flowers in a vase. They are such satisfying things to grow because like hungry teenagers they put on such a phenomenal growth spurt during the growing season; you can literally watch them change day by day. One minute they are tiny little plants with a few green leaves, the next they are towering monsters with huge, dinner plate flowers. The reason for this endless diversity in shape and form is that dahlias have more chromosomes than most other plants (eight sets as opposed to two), so when they cross-fertilise, there is much more variability in the offspring.  They are loosely arranged into 10 groups according to their flower shape – Single-flowered, Anemone-flowered, Colarette, Waterlily, Decorative, Ball, Pompon, Cactus, Semi-cactus and Miscellaneous – and there are hundreds of varieties to choose from, whether your taste is for bold form and clashing colour or simple, single flowers in muted tones. ‘Dahlias spell excitement,’ wrote Christopher Lloyd, ‘and we can all do with some of that in our lives.’