How to grow dianthus

What are Dianthus?

There are many forms of Dianthus, several of which are prized for their scent. Pinks include ground-hugging alpines, traditional garden pinks and popular bedding varieties. Biennial

Biennials are plants that complete their life cycle over the course of two years. In the first year, biennials typically produce leaves and roots but no flowers. In the second year, they flower and produce seeds before dying. Some common biennials include foxgloves Digitalis, honesty Lunaria annua and viper's bugloss Echium vulgare.

sweet williams are a versatile, cottage-garden staple, ideal for cutting, bedding and borders. Clove-scented, hardy carnations may also be grown in borders but cut-flower varieties require greenhouse conditions. 

Choosing Dianthus

The main decisions are based on whether your garden offers the right growing conditions or if you are able to provide them in a container. Beyond that there is a range of flower colours – generally white, pinks and reds, but look out for deep purple, green and yellow too.

If you have a sunny, free-draining spot, there are many Dianthus that you can grow. These include short-lived Dianthus for bedding and containers, old-fashioned and modern varieties of garden pinks, border carnations and many alpine pinks. Colour-wise, many of these are pink but in a great variety of shades, as well as white and a range of reds, many with a contrasting eye, border or striped pattern.

A few alpine pinks are so intolerant of excess soil moisture that they are best grown in containers housed in a cold frame

Cold frames are glaze box-like structures made from brick or wood with a  hinged or removable, glazed, sloping lid. Useful to protect plants from cold weather over winter or acclimatise (harden off) young plants in spring and provide extra warmth for tender crops in summer.

or alpine house. 

Coldframes and mini-greenhouses

How to grow alpines

Perpetual-flowering carnations and Malmaison carnations, both grown for cut flowers, require the protection of a greenhouse or conservatory. The available varieties of Malmaisons have flowers in shades of pink, red or white, and are richly scented. Perpetual-flowering types have varieties in an astonishing range of colours – not just reds, whites and pinks but orange, green, smoky grey striped with bright pink and peach flecked with lilac. Sadly, not all are scented so check if this matters to you.

To help you choose from the many available Dianthus, look out for those that have received the RHS Recommended: Award of Garden Merit as these have been assessed and are known to perform well. Use the RHS Find a Plant tool to browse images and focus your search on your particular requirements.

Buying Dianthus

Garden centres are good places to find short-lived Dianthus for bedding and containers, including varieties of China pinks (D. chinensis) and sweet williams (D. barbatus). They will also stock some of the more robust alpine and rockery types, and probably a few perennial

Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

garden pinks. 

For more specialist alpine species, or particular named varieties, mail order specialists are a better bet. Use our Find a Plant tool to find stockists once you have made your choice. 

Annual and biennial pinks are also easy to grow from seed, available in retail outlets and by mail order.

Buying: garden centre plants

Buying: mail order plants

While pinks are generally easy to find, carnations can be more of a challenge. With hardy border carnations, perpetual-flowering and Malmaison types, only small numbers are produced each year in a limited range of varieties. However, some specialist nurseries may have them available by mail order; alternatively, try plant fairs and shows. 

There are National Collections of older perpetual-flowering carnations and Malmaison carnations, helping to ensure that some cultivars are conserved for the future.

When to plant

Most Dianthus are best planted outside in spring. However, many are sold when in flower during the summer, when they can also be planted, as long as the soil is kept moist while they establish. 

Where to plant

Hardy Dianthus grow well in full sun on free-draining soil. If your soil is prone to waterlogging, grow Dianthus in containers or raised beds so you can provide the good drainage they require. There are a few specific requirements for particular Dianthus, which are detailed here: 

• Alpine species benefit from the sharp drainage of a raised bed or trough
• Most Dianthus prefer neutral to alkaline soils. Annual and biennial
  

  Biennials are plants that complete their life cycle over the course of two years. In the first year, biennials typically produce leaves and roots but no flowers. In the second year, they flower and produce seeds before dying. Some common biennials include foxgloves Digitalis, honesty Lunaria annua and viper's bugloss Echium vulgare.

  Dianthus will tolerate more acidic soils, as will some that are suitable for rock gardens, such as D. glacialis, D. microlepis and D. pavonius
• Most Dianthus are fully hardy, except for perpetual-flowering and Malmaison carnations which are usually grown in a frost-free greenhouse

How to make a raised bed

Sink and trough gardening: plants for

Soil types

How to plant

Dianthus like well-drained soil and will not thrive where the soil is waterlogged

Describes soil or potting compost that is saturated with water. The water displaces air from the spaces between soil particles and plant roots can literally drown, unless they are adapted to growing in waterlogged conditions. Waterlogging is common on poorly drained soil or when heavy soil is compacted.

. To improve drainage in borders, dig in plenty of well-rotted organic matter such as leafmould or garden compost

Can refer to either home-made garden compost or seed/potting compost: Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

before planting. Although it can be tempting to add grit, sand or gravel to improve heavier clay soils, you need extremely large quantities to make a noticeable difference. Incorporating organic matter not only improves structure and drainage but boosts fertility too.

If you buy container-grown Dianthus, plant them at the same soil depth as they are in the container, ensuring the lowest leaves are above soil level. Mail-order plants are likely to be smaller and may need planting into larger pots to grow on for a few weeks before planting out. Malmaison and perpetual-flowering carnations are best kept permanently in pots.

Organic matter: how to use in the garden

Bedding plants and displays

Perennials: planting

Watering

Water well after planting. Plants in containers will need checking regularly and may need daily watering in hot weather. Established Dianthus in borders should only need watering during very prolonged dry spells.

Watering

How to water containers

Feeding

Dianthus grown in the ground are unlikely to need additional feeding. Plants in containers, especially short-lived bedding types, will benefit from additional fertiliser – see our advice below. Perpetual-flowering and Malmaison carnations will also benefit from applications of an organic liquid fertiliser during the growing season

The period of time when an individual plant is in active growth. This will depend on the local climate and light levels, and can vary between different plants, although it is broadly from spring to autumn.

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Fertilisers

Homemade fertilisers

How to feed plants

Overwintering

Most Dianthus are fully hardy and are more likely to be damaged by winter wet than cold. Good drainage will help protect them, though some alpine species will need to be overwintered under cover, without any extra heat. 

Perpetual-flowering carnations are tender and are normally grown under glass in a greenhouse or conservatory year-round. They can flower throughout the year if they have enough light and the temperature remains at 10°C or more. 

Malmaison types flower mostly in summer and need shelter but no additional heat over winter. 

Caring for older plants

Some perennial

Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

Dianthus are short-lived, and others tend to go bare in the centre. Taking cuttings

A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year.

every two or three years will ensure a constant supply of good flowering plants. See Propagation below.

Disbudding carnations

Carnations naturally produce a spray of around six flowers on each stem. To produce larger flowers, the number per stem is reduced by disbudding – gently nipping off two or more buds once they are large enough to remove. To produce florist-style carnations, remove all but one bud

A bud is a small, undeveloped shoot that contains the potential for new growth. Buds are typically found on stems, where they can be apical (found at the tip) or axillary (found between leaf axils) and may develop into leaves, shoots or flowers.

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Deadheading

With both pinks and carnations, removing faded flowers down to the next bud or side shoot will keep plants looking tidy and encourage more flowering. 

Deadheading plants

Support

Carnations of all types generally need support for their large flower heads atop tall, narrow stems. Wire rings supported on thin canes are the traditional technique. Pinks are much shorter and generally self-supporting. 

Perennials: staking

Dianthus are generally propagated from seed or by cuttings

A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year.

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• Alpine species: sow seed in containers in a cold frame
  

  Cold frames are glaze box-like structures made from brick or wood with a  hinged or removable, glazed, sloping lid. Useful to protect plants from cold weather over winter or acclimatise (harden off) young plants in spring and provide extra warmth for tender crops in summer.

  from autumn to early spring
• Annuals
  

  Annuals are plants that complete their life cycle in one growing season. They are generally easy to grow from seed or can be bought as young plants from garden centres. Annuals are ideal for growing in summer containers and filling gaps in borders. Some examples of annuals include sunflowers, cosmos, sweet peas and zinnia.

  : sow seed in containers at 13–15°C in early spring
• Biennials: sow in situ in autumn, or in containers at 13–15°C in early spring to flower in the same year
• Border carnations: take cuttings from non-flowering shoots in summer or propagate by layering after flowering
• Pinks and other perennial
  

  Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

  Dianthus: take cuttings from non-flowering shoots in summer
• Perpetual-flowering and Malmaison carnations: take cuttings from non-flowering shoots in late winter. Once the young plants have developed six pairs of leaves, encourage branching by removing the tip of the shoot, known as pinching out or stopping
• Pinks and carnations: take cuttings known as pipings by gently tugging the top of a non-flowering shoot, or a side shoot, so it comes away from the rest of the stem. It is then treated like a softwood cutting. Pipings can sometimes be found when you buy cut-flower carnations

How to sow seeds indoors

How to sow seeds outdoors

Cuttings: softwood

Layering

Dianthus can be short-lived. Although many are technically perennial

Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

, most Dianthus used for bedding displays are best replaced after their first year. Regular propagation from cuttings

A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year.

(see Propagation above) will keep garden pinks healthy and flowering well.

Aphids and slugs can be a problem on Dianthus grown outside. 

Aphids

Slugs and snails

Aphids, thrips, tortrix moth caterpillars and spider mites may damage carnations under glass.

Glasshouse red spider mite

Glasshouse thrips

Tortrix moth caterpillars

Rust can affect the leaves and stems of carnations, pinks and sweet williams.

Rust diseases

Preventing pest and disease problems

Managing pests and diseases without chemicals

If you are a member of the RHS, you can use our online Gardening Advice service for any gardening questions.