Always use a clean and sharp pair of secateurs or snips when deadheading any plant to ensure the plant doesn’t develop diseases.
To promote continuous flowering, dahlias need to be deadheaded regularly, especially the smaller flowered varieties that produce copious amounts of blooms all at once.
As well as deadheading, gardeners need to be pinching out the plant’s shoot tips. When the main stem gets to about 40cm (16in) tall, pinch out the tip, just above a pair of leaves. This will lead to branching at this point, resulting in a bushier plant.
Gardeners who are growing these plants for giant flowers or for cut flowers need to nip out the smaller flower buds behind the central larger bud.