For lasting benefits and continued flowering, follow this easy guide for deadheading familiar plants in the garden
Houzz UK contributor and award-winning landscape and garden designer. Claudia de… More
When flowers fade they lose their attraction, leaving borders and beds less attractive. Deadheading directs energy into stronger growth and therefore more flowers. I get asked a great deal about why we need to deadhead plants, especially how and when to do it. This is not about pruning, as such, but more about prolonging the flowering of many common garden plants. Below is a rough guide to deadheading some of most familiar plants and shrubs. Watch this space for a detailed series of guides on pruning in the coming months.
When the flowers on roses start to wilt or fade, it is best to deadhead as the petals can damage the leaves. In terms of simple deadheading – rather than pruning, which is done in late winter or March – there are two types that can be done on hybrid and floribunda roses.
For hybrid roses, which bear one flower on a single stem, cut the flower stems back, which ensures you have a strong stem to support any new blooms. Cut to around 15cm of an out-facing shoot, meaning one where the bud is facing the direction in which you wish the rose to grow, and make an angled cut just above the bud.
For floribunda roses, which bear clusters of flowers on a single stem, you can cut off the faded flowers from behind the head and then trim back the stem to around 15cm. Repeat flowering roses do best when you cut back the entire cluster to around 15-22cm as this will ensure a more vigorous second flowering.
On rambling and climbing roses these clusters are called trusses, and many people like to leave some of these in place as they turn into edible (rose)hips, which birds enjoy eating.
For all deadheading of roses, it is best to use secateurs that are sharp enough to avoid tearing the plant. Make sure you do cut down to a bud which will then form sideshoots for more flowers. Some varieties are not repeat flowering but doing this small amount of cutting back will still energise the plant. Make all cuts at a 45 degree angle to prevent water getting in and damaging the plant, which may lead to fungal disease.
To prevent ‘balling’, where the bud doesn’t open due to the rain and tends to make the flower bud look like a closed ball, remove the outer layers of petals on a bud to allow the bud inside to open.
Just starting out with gardening? Learn the lingo every novice gardener should know
Depending on the variety of hydrangea, different methods apply. For mopheads and lacecaps, the latter pictured here, you can either deadhead the flowers immediately as they die off or leave them on the plant over the winter months if you don’t mind the blooms becoming dry or turning brown in colour. There is a benefit to leaving them on until the following spring – it will help to protect the new season’s growth against frost. Come spring, you can chop them off: in this instance, cut back the spent flower to the nearest bud on the stem below.
With lacecap hydrangea, which are hardier, it is probably best to cut the flower back, once faded, to the second pair of leaves below the head.
If you have climbing hydrangea I would suggest you cut back overlong shoots – ‘leggy’ ones that don’t have much foliage on them – as soon as they have flowered.
For the paniculata and arborescens varieties, remove the deadwood in the spring, cutting back last year’s stems to a healthy pair of buds in order to achieve a good framework.
Hydrangea quercifolia needs minimal pruning, just enough to remove the dead, overlong stems.
Rhododendrons and Azaleas, Camellias and Lilacs
With Azaleas and Rhododendrons, you can snap off the spent flower truss (which is the same as a cluster) after flowering, but be careful not to damage the new young growth coming through underneath. Some of the plants in your garden may be too big to do this to as they can grow to huge proportions. If that is the case, I suggest you do this with your younger plants and any parts of the larger ones you can reach easily. If you don’t deadhead these shrubs, the plant will waste all its energy into making big fat seedpods, inhibiting growth and so limiting any flowering the following season.
Camellia flowers are also removed by getting your hand behind the flower head and pinching off the spent blooms.
With lilac and buddleia flowers, you will need to remove them using secateurs, cutting to the base of the flower stem. This deadheading will improve the appearance of the plant and help to encourage the production of new blooms on the shrub.
Reasons to plant creeping and ground cover plants in your garden
The more tender annuals, such as Cosmos bipinnatus and Cosmos sulphureus, need to be deadheaded in order to keep them blooming. Cosmos will flower prolifically all summer long, and if you keep deadheading you will have a constant see of bright-coloured daisy flowers. Make sure when you do deadhead that you cut the stem back to the first leaf rather than just removing the flower head.
This is another plant that needs to be deadheaded regularly or picked in order to remove the seedpods and so encourage more flowers to develop. Keep on top of removing the seedpods on sweet peas and, if you go away, make sure a neighbour or friend/relative comes in to keep cutting back or you will have none of these wonderful scented flowers to come back to.
Foxgloves, delphiniums and lupin
The tall, flowering stems of foxgloves, delphiniums and lupin can be removed, but this will only produce small flowering spires lower down the stem. These plants cannot be guaranteed to produce a second flush of flowers or if they do, they will not be as good as the first ones earlier on in the season. However, if you prefer not to deadhead and you leave the old dead flower spikes on the plant, you will have tall spires of green pods full of seeds which will naturalise around the garden. Delphiniums will sometimes flower again in September if you cut them back, but remember to leave some foliage. They will look a bit tatty for a while, but give them a liquid feed and keep up any slug treatment until the new leaves start to appear at ground level. Then, later in the year, you may be rewarded with a second flush of blooms.
Geraniums and pelargonium
These will continue to bloom if you keep deadheading. If you have the patience, you can remove each individual flower once it has gone over, or wait until the entire cluster is spent and remove it from the base where it meets the main stem. Try to remove fallen petals from the soil below as these will promote fungal growth, especially on damp soils.
As pelargonium grow on straight stems you can be a little more drastic earlier on to create a bushier plant by pinching out (cutting off) the tip of the young plant when it reaches 7cm. This will encourage the plant to form sideshoots (this method of pruning to boost the bushiness of a plant is what pinching out refers to).
Pelargonium leaves may cause some people to have skin irritation so wear gloves.
It is always a good idea after any deadheading to give your plants a feed with a high potash fertiliser.
Who doesn’t love a bit of lavender in their garden? And as long as you have planted this fragrant Mediterranean plant in a sunny sheltered spot and into very well-drained soil, you should have strong plants for many years to come.
English lavender varieties that flower in June and July should be deadheaded or given a light clip over straight after flowering, avoiding any cuts into old wood. This light clipping will encourage bushy side growth and ensure you have a more compact plant.
The stoechas cultivars, also known as French lavender, that flower in May need regular deadheading, making sure you remove each of the heads along with a bit of the stalk after they have faded (or ‘gone over’), leaving the rest of the plant as is. This regular deadheading will make sure the plant continues to flower, albeit rather more weakly, well in the autumn.
Nepeta (catmint), including the Six Hills Giant or Walker’s Low varieties, is often grown as a lavender substitute. With these, you can simply chop the plant back throughout the year after flowering and you will be blessed with continuous blooms well into the autumn months.
Tulips and daffodils
Deadheading bulbs such as daffodils and tulips unfortunately doesn’t lead to new blooms, but if you are not using the seed for propagation purposes, then it is better to remove the spent flowers (if you are using the seed to propagate, wait until they dry on the stem and the you can collect the seed.)
Cut back the flower stalk back to its base and leave the foliage on the plant. By removing the seedhead of the plant, energy will be conserved and will be directed towards next year’s display. You should then wait about six weeks to cut the remaining leaves and dead foliage. Even though you have removed the flower heads during the six weeks before removing the leaves, make sure you have kept watering and feeding the bulbs with a general purpose fertiliser.
Bulbs such a crocuses and snowdrops do not need deadheading, these will naturalise without you having to snip the heads off.
Petunias and pansies
If you have bought or planted up pots, window boxes or hanging baskets with annual plants such as petunias (the red flowers above) or pansies, it is important to deadhead to stop the flowers going to seed once they have wilted or started to drop. If you do this, you will be rewarded with a succession of new blooms for the rest of the season. The flowers on petunias can be quite sticky to touch but are easily removed by pinching the flower off gently with your fingers. It is easy to remove just the petals, so make sure you see that you have taken the small pointed seedpod in the middle where the petals were.
In the middle of the blooming season you can actually chop the whole plant back to around 12cm. This seems very drastic but, even if if there are some new flowers to come, you will be rewarded with a bushier, healthier plant with more flowers that will bloom for many more weeks to come.
There are, however, some newer varieties of petunias that are ‘self cleaning’ and also some varieties of busy Lizzie or impatiens – also popular hanging basket or window box plants – that will require minimal deadheading.
Day lilies or hemerocallis
Day lilies, otherwise known as hemerocallis, only bloom for one day, hence the name, but they produce lovely trumpet-like flowers and are a wonderful addition to the late summer border. Once a lily flower has been pollinated it will start to shrivel and make the plant look messy but it will also start to form a seedpod. The best way to remove the head of a lily is to simply snap off the old flower head – or use a pair of secateurs – and make sure you don’t knock off any new flower buds which are about to open. This is also a good time to remove any soggy looking or diseased leaves and stems, which are quite common on these plants. Deadheading and keeping the plant healthy may also help prevent hemerocallis gall midge, which can form in the buds. If you suspect this has happened to your lilies, remove and destroy the infected buds.
Dahlias have really come back into fashion again, especially as a cut flower. If you keep deadheading dahlias, you will encourage the plant to produce new blooms. To deadhead, cut the flower after it has faded or gone over by following the flower stem back to where it meets the main stem. You will be blessed with a continuous display of vibrant blooms well into the autumn or until the first frosts.
Do you have any deadheading tips to share – or any photos to show us of your beautiful garden blooms? Show/tell in the Comments section.