Why does this happen? Well, the answer is quite simply. All a plant wants to do is grow as big as it can and multiple – it is genetically hard-wired to do just that. It will invest a lot of energy into getting pollinated and ultimately, produce seed. If you remove spent flower heads before seed heads start to grow, then your plant will try again and again and display more blooms.
I should point out, some plants won’t respond to deadheading, but I’d still recommend you do this as it will concentrate the plants precious energy on foliage and root production and give an even better display for next year. Obviously, this doesn’t apply to varieties that produce attractive seed heads – they can look great when all other plants have wilted under the early frosts of Autumn.
When deadheading, always ensure that you remove spent flowers without damaging your plant. Cut or pinch when possible and avoid pulling as this may break or even uproot your plant. I prefer to hover around my flower borders with a bucket in hand to collect the deadheads for my compost heap.
Plants that appreciate deadheading
Pansies and Violas – they love to be deadheaded! I have found that if I start in March when the first flowers appear, I can have blooms right into late October! Cut back straggly stems to produce fresh, vigorous growth.
Geraniums and Pelagoniums – always love a good deadheading. After All, they can look terrible if neglected and will reward with plenty of new growth.
Herbaceous Perennials such as foxgloves, lupins and delphiniums – you sometimes get extras blooms if you deadhead, but more importantly, you’ll encourage plenty of new leaf and root growth.
Roses – don’t let the ‘hips’ form. Keep on removing deadheads to prolong the flower season and save energy for next year’s flowers.
Daffodils and other bulbous spring flowers – trim off the seed capsules as they appear for a more robust bulb clump next year. Don’t trim the leaves as many bulbous plants will draw nutrients out of the leaves as they wilt and rot. Instead, gently tie them to keep them tidy.
Sweetpeas – not quite deadheading, more like live-heading! Cut blooms as they appear and put in vases around your home. This will encourage plenty more flower production. If you let the pea pods form, then you have already weakened the plants capability to produce more flowers.