My father grew dahlias, so I suppose it’s not surprising I caught the bug. I didn’t start keeping the tubers over winter until 1974, when I had one each of 15 varieties. Only one -‘Gay Princess’, a tall pink waterlily has survived to today. I grow 30 varieties now, about 1000 plants in total, plus some for friends.
One or two tubers of each variety are lifted in mid-November, washed clear of soil, and stored under peat in a frost free greenhouse. At the end of December, I inspect them. They seem to have come through the recent cold spell, except that many are slimy about the stem; they’ve been given another dusting of sulphur.
On 1st March, I’ll water them and switch on the underground heating cable. Shoots will appear in April for cuttings or division.
They are potted on to 3½ inch pots, and then into 5 inch in mid-May, hardened off and planted out in mid-June. I’m unsuccessful with about 10% of the tubers, so I buy replacement plants or newer varieties.
Dahlias can be grown on the same patch for years so long as it is well manured each spring. I apply ‘Growmore’ when planting out, and rose fertiliser twice during the season. I am not troubled with earwigs, but last year capsid bugs had several meals from the new shoots, and mildew affected the leaves in September.
Although I am not interested in exhibiting dahlias (too much of a commitment!), I do aim for better blooms and longer stems by removing all buds that appear before mid-July, and then once a week remove all side shoots from the two upper leaf axils on each branch. Most summers they need a good watering twice a week.
From mid-August to mid-October, surplus blooms are sold at charity stalls at the Saturday market. At three for a pound, they sell fast!
by Peter Block
