Nick said gardeners will need to cut them down as “early as possible” to get them to re-flower.
He explained: “As soon as they finish flowering, cut them down before they go to seed and then you will get a much stronger second flower than you will if you don’t.
“Feed them well, water them well and you should get a good flower in September.”
Delphiniums, which are also known as Larkspur, are native to the northern hemisphere but can also be spotted on the high mountains of tropical Africa.
