How to get more flowers
Many flowering plants can be encouraged to produce better and longer-lasting displays with the minimum of effort. A plant produces flowers in order to reproduce and ensure the survival of the species. Once a plant has flowered and fertilisation has taken place, it tends to put its energy into producing seed at the expense of more flowers. With some popular plants such as zinnias and sweet peas, flowering can stop altogether. You can prevent this happening by simply removing the flowers as they start to fade, thereby preventing the formation of seedpods. This technique is known as deadheading. By removing blooms as they fade, deadheading also improves the current display.
Some flowering plants, such as lady’s mantle, are worth deadheading to prevent them from self-seeding all over the place and causing a weed problem. All flowering plants respond to an annual application of high-potash fertiliser, such as a tomato feed or a dressing of sulphate of potash which will also promote flower production.
How you go about deadheading will depend on both the type of flowers and your attitude to gardening – I’ve seen some particularly tidy gardeners removing blooms fastidiously when the flowers are barely over while others wait until the blooms have turned brown. Generally, the ideal time is somewhere in-between. If you can get into the habit of deadheading as you walk around the garden, flowering plants will get the once over at least once a week from early summer to early autumn. With any luck!
How to deadhead
How you remove the flowers from a plant should depend on the type of growth it produces.
- Long flower stalks. Plants that produce one flower head at the end of a stalk, such as pelargoniums, should have the fading flower removed along with the stalk – snapping it off cleanly from the stem. Bulbs, such as daffodils and tulips, are the exception. These should have the flower cut off leaving the stalk intact. Repeat-flowering plants (such as roses) and those that produce flower spikes (such as delphiniums and foxgloves) are also treated differently – see below.
- Short flower stalks. Plants that produce flowers on short stalks, such as fuchsias, should have the fading bloom removed by pinching off the stalk behind each fading flower between finger and thumb.
- Masses of flowers. Life’s too short to worry about plants, such as alyssum, that produce masses of tiny flowers. But if you want to preen a few pots on the patio try using an old pair of scissors to make the job easier.
- Flower spikes. Many border flowers that bear their blooms on tall spikes, such as foxgloves and delphiniums, antirrhinum, hollyhock, lupin and penstemon can be encouraged to produce a second flush of smaller spikes later in the year if they are also deadheaded. When the last of the flowers start to fade on the spike, simply cut the whole spike back using a pair of secateurs to just above the highest sideshoot lower down on the stem. With luck, many smaller sideshoots will then develop and bloom towards the end of the summer.
- Repeat flowering. Many repeat-flowering plants, such as bush roses, will flower better and for much longer if regularly deadheaded throughout the flowering season. Floribunda roses (cluster flowered) should have each fading bloom cut from the cluster until the last one remains. As this fades, cut back the cluster to just above a leaf joint, about six inches below the flower cluster. With large-flowered, hybrid-tea roses, cut each faded bloom back to just above a leaf joint, about nine inches below the flower. By cutting back into thicker stems like this, stronger flowering shoots and a greater number of flowers will be produced. Feed roses with a rose fertiliser after the first crop of flowers have been deadheaded to encourage more blooms.
Relay flowering. Some multi-stemmed plants which produce a lots of flowers on stems produced during the current season, can be deliberately pruned to encourage some stems to flower earlier or later than others, thereby spreading the flowering display over a longer period. Some clematis are a case in point, but this technique also can be tried with vigorous shrubs such as lavatera or the butterfly bush (Buddleja) which are normally cut back hard each spring. In this case, instead of cutting all the stems back hard, cut back about two-thirds, leaving the others to flower earlier than the hard-pruned stems.
A few clump-forming perennials that produce a massed display of blooms, such as coreopsis, phlox and helenium, can have their flowering spread over a longer period by selective cutting back. All you need to do is cut back by half about one-third of the stems before they produce flowers. These will then throw several sideshoots each which will flower later in the summer, effectively extending the season of colour.
Flowering shrubs worth deadheading regularly
Hybrid-tea roses
Floribunda roses
Fuchsia
Choisya
Perovskia
Hypericum
Other techniques to try
Eternal youth. Some plants produce their best displays of flowers and foliage when young and vigorous. Herbaceous plants, such as achillea, produce their best displays if kept growing strongly. All you have to do is to lift the plants every couple of years and divided the clumps and they will reward you with bigger and better displays. Shrubs, such as red-stemmed dogwoods, produce brighter and more colourful bark on new growth. So, by pruning them back hard each spring, you can get the best displays possible. This technique also works with variegated dogwoods, which produce larger and more decorative foliage on new growth. Similarly, to get the attractive rounded leaves of Eucalyptus gunnii used in flower arrangements, you need to keep the growth juvenile. The easiest way to do this is to grow the plant as a shrub and cut back all new growth each spring.
Herbaceous plants to divide regularly
Achillea
Aconitum
Aster
Geum
Heuchera
Solidago
Fresh foliage. Some flowering perennials, such as hardy geraniums, can start to look a bit tatty towards the middle of the summer as the effects of drought and pest and disease attack take their toll. You can improve the overall appearance of the plants and, if you are lucky, get another flush of blooms in late summer by cutting all the old foliage right back almost to ground level using a pair of shears. The new growth will look fresh and neat until the autumn. Water plants thoroughly after cutting back and give them a boost by applying a high-potash fertiliser such as rose or tomato food.
Plants grown mainly for their attractive foliage, such as coleus and artemesia, will maintain a neat habit and fresher looking foliage if they are prevented from flowering altogether. In this case, trim the flowers from the plant before they start to open.
Plants to cut right back
Centaurea montana
Lamium
Nepeta
Hardy geranium
Geum
Viola
PS
If you are going on holiday, remove all the flowers from repeat-flowering plants before you go. Concentrate on container plants as well as those in prominent positions such as near to the patio. When you get back, you’ll be rewarded with a sea of fresh flowers rather than a dreary crop of seedheads.
