how to plant, grow & care for dianthus
complete growing guide
Dianthus are biennials and short-lived perennials which flower prolifically when they are young. Commonly referred to as garden pinks for their serrated petals that look like they’ve been cut with pinking shears, the genus also includes carnations (Dianthus carophyllus) and sweet williams (Dianthus barbatus). We tend to grow sweet williams as biennials while English garden pinks are grown to last for several years. With wonderful scent and incredible vase life dianthus plants are a staple in cottage and cutting gardens. The petals are edible too, so you can decorate salads and puddings to your heart's content. Take a look at our range of dianthus plants and seeds and find your new favourite.
- Common name Sweet williams, pinks, carnations
- Latin name Dianthus
- Type Short-lived perennials
- Height 15-60cm high
- TLC rating Easy
- Aspect Full sun
- Planting position Front of border, cutting garden, containers
- Suitable for pots Yes
- Good for pollinators Yes
- Good for cut flowers Yes
how to grow dianthus
where to grow dianthus
Soil type: Sweet williams and pinks are most long-lived and floriferous when planted in well-drained, neutral to slightly alkaline soil, but they will tolerate a range of conditions.
Aspect & position: Plant your sweet williams and pinks in an open position in full sun. A position in shade can reduce flowering.
when to plant dianthus
Dianthus seeds can be sown in spring or summer, whereas dianthus plants are best planted in spring, summer, or early autumn.
how to plant dianthus
sowing dianthus seeds
Sweet williams (Dianthus barbatus) can be grown from seed or bought as plugs or small plants. To grow sweet williams from seed, it’s best to sow the seeds in May-July for flowers the next year. However, some varieties, such as ‘Sweet Purple White Bicolor’ and ‘Sweet Pink Magic’, can flower the same year if started in a heated propagator in January, February, or March and planted out in April or May.
Sow seeds thinly on the surface of seed trays, modules or pots and place in a cold frame or unheated greenhouse. Once germinated, thin seedlings in pots and modules to one seedling or pot up ones sown in seed trays into individual pots.
Grow on somewhere sheltered, keeping well-watered but not soggy and transplant into final positions, spaced 30cm apart, when the roots have filled their pots (usually in early autumn).
Sweet william seeds can also be sown direct into well-prepared soil once the risk of frosts has passed. Sow thinly on the surface, keep moist and thin to 30cm apart. These will flower very well the summer after sowing and can be kept for another year (most successful on free draining soil in mild winters).
Pinks like the clove pink, Dianthus caryophyllus (also called a border carnation) and the fringed pink (Dianthus superbus) can be grown from seed. Sow under cover in spring, covering seed only very thinly as some light is needed for germination. Pot up and grow on in a cool but frost-free place for planting out when frost has passed. Pinks tend to flower in their second year and then last a few years.
planting dianthus plants
Plant out English garden pinks and sweet williams between spring and autumn. Prepare a hole in the ground large enough for the root ball and plant gently into it, firming the soil lightly back around with your hands. Keep well watering in dry spells for the first 6 weeks; once established they cope well in dry conditions.
growing in dianthus in pots
Dianthus can be planted into containers for summer displays. Small varieties such as ‘Sunflor Purple Wedding’ look fabulous in small pots as a table display.
how to care for dianthus
Newly planted dianthus will need watering thoroughly every few days in dry spells but once they are established, they are very drought resistant. Avoid overwatering your dianthus plants as they don’t like to be soggy or waterlogged.
Perennial species can be fed once in late spring with an organic fertiliser such as comfrey or chicken pellets. Dianthus plants in containers will need feeding fortnightly with a liquid feed.
Taller dianthus varieties may need staking, especially on windy sites.
Regular deadheading of dianthus plants can increase the chances of repeat flowering. Deadhead any spent dianthus flowers that you have not picked for the vase at least weekly in summer to keep plants flowering. Remove the individual flowers and once all flowers on a stem have gone over, cut the whole stem back to the base to keep the plant tidy.
Dianthus plants are fairly short-lived and can become woody after a few years. At this point it’s best to dig them up and replace them with new ones.
dividing & propagating
Perennial pinks can be lifted and divided in spring or propagated by stem cuttings. To take stem cuttings from your plant choose a non-flowering shoot and cut or pull it from the base. Remove the lower leaves and place your cuttings around the edge of a pot filled with compost. Once the cuttings have rooted and are growing well, usually after a few weeks, pot into individual pots and grow on. Cuttings of perennial pinks can be taken any time from spring to late summer.
If frosts kill the foliage of established perennial species, you can cut it back to a few centimetres. Mulching around the crown can help to protect the roots from winter wet and cold.
- Sow seed of many species.
- Plant out small plants once the worst of the frosts have passed.
- Sow sweet williams.
- Cut or deadhead flowering plants regularly. Keep plants in pots well-watered.
- Plant sweet williams out into final positions in the garden.
- If needed, add mulch to protect from winter wet & cold.
pests, diseases & common issues
viruses and diseases
Dianthus can suffer from fungal diseases including rust and wilts. These are most often a problem when pinks are grown indoors for cut flowers and ventilation is poor. Most gardeners growing on free-draining soils are unlikely to experience problems and should just cut off any wilted or rusty growth if it is seen.
Some dianthus are also prone to viruses which show themselves as weak or distorted plants and these should be destroyed.
Aphids can be a problem for dianthus plants, as can slugs, snails and rabbits. Aphids can be blasted off with a jet of water. Slugs and snails may be kept away with a ring of sharp sand around the plant; for rabbits you will need to surround the plant with wire.
This is usually caused by growing dianthus on soils that are too soggy. Dianthus grow best and last longest in free-draining soils.
why are my dianthus turning brown?
In autumn when frosts hit, browning is likely to be natural die back and perennial plants should regrow in spring. At other times of year, it may be the result of overly wet soil causing the plant not to thrive or simply the plant reaching the end of its life cycle.
what is eating my dianthus?
Aphids can be a problem on dianthus, but these can be blasted off with a jet of water. Dianthus plants are often considered deer resistant, so it is fairly unlikely that deer are troubling your pinks and sweet williams, but slugs, snails and rabbits are all partial to dianthus plants and could well be the culprits.
frequently asked questions
are dianthus flowers edible?
Dianthus petals are edible and make wonderful decorations for cakes and salads. The petals have a slightly sweet and spicy, clove-like flavour.
are dianthus plants evergreen?
Yes, most forms of dianthus are evergreen or semi-evergreen.
do dianthus plants grow back every year?
Pinks and carnations are short-lived perennials, meaning they will live for a few years before they start to go woody and need replacing. Sweet williams are usually grown as biennials, meaning they will grow in their first year and bloom and then die in the second year.
do dianthus plants spread?
Pinks are generally not considered to be spreading plants. Sweet williams may spread by self-seeding if you do not deadhead the flowers.
can dianthus grow indoors?
You can start your dianthus seeds indoors before planting out in the garden. Some dianthus plants, mainly carnations, will be happy to grow indoors but most will grow best outdoors where they can get a lot of sunlight.
will dianthus survive winter?
Garden pinks and sweet williams are hardy and will survive most winters in the UK. In areas that have particularly wet or cold winters, mulching around the base of dianthus plants can help to protect them. Plants grown in pots may also need additional protection.
what is the difference between dianthus and carnation?
Carnation is the common name for Dianthus caryophyllus which is a species of Dianthus. Dianthus is a genus of around 300 species of flowering plants, including carnations, sweet williams (Dianthus barbatus) and pinks (Dianthus plumarius and others).
are dianthus plants poisonous to dogs and cats?
Dianthus plants can be mildly toxic to dogs and cats. Dogs and cats may experience gastrointestinal upset if they ingest dianthus plants (particularly the leaves). Fortunately, the effects are usually mild, but it may be worth keeping your sweet Williams and pinks away from any pets that are particularly prone to nibbling on plants.
what is the meaning of dianthus?
Dianthus is said to come from the Greek ‘dios’ (god) and ‘anthos’ (flower) – ‘divine flower’ or ‘flower of Zeus’.
how tall do dianthus grow?
The dianthus plants and seeds we sell range from 15cm to 60cm tall.
how long does dianthus bloom?
Individual dianthus flowers can last 2-4 weeks but whole plants can flower for 3 months or more.
how to cut & arrange dianthus
Dianthus last really well as cut flowers, typically two weeks but sometimes up to one month. Remove the bottom leaves from the stem and sear in hot water for 30 seconds before arranging.
Dianthus barbatus ‘Green Wicky’ is a more unusual form of dianthus and one of my favourite foliage plants to use in cut flower arrangements. It has beautiful fluffy green domes instead of the serrated edged flowers more common in other dianthus forms.
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