Deadheading Annuals and Biennials

Removing any dead and faded flowerheads promptly can lengthen the flowering period of plants and greatly improve their looks. Dead heading prevents a plant from setting seed, which means that its energy is used to produce additional flowers rather than producing seedheads. However, do bear in mind that some plants, such as Hibiscus trionum, and honesty (Lunaria), produce attractive ornamental seeds or fruits, in which case dead heading should be avoided. You should also refrain from deadheading plants whose seeds are required for growing again during the following season.

Deadheading is easily carried out by snapping off any faded flowers between the fingers and thumb, breaking the stems cleanly. If the stems are tough or there is a danger of disturbing the plant as the dead flowerheads are removed, use a pair of sharp scissors or secateurs instead.

A few annuals and biennials, such as poppies (Papaver), do not produce any more flowers after dead-heading, whereas the flowered stems of lupins (Lupinus) can be cut back to the base when the first flower flush has faded, rewarding you with a second flush of flowers.