Deadheading will prevent them setting seed and so use their energy producing a further flush of blooms later on. Plants that respond well to deadheading include annuals such as Ageratum, Alyssum, Antirrhinum, Calendula, Centaurea, Cosmos, Dahlia, foxglove, Californian poppy, sweet peas and viola. Perennials worth deadheading include delphiniums, Erigeron, hardy geraniums and lupins.
scissors, secateurs or shears.
easy