Poet's Carnation - Dianthus barbatus: planting, sowing, care

Description and Botany

Sweet William, or beard pink (in Latin Dianthus barbatus), also known as “ready-made bouquet”, is an herbaceous plant that belongs to the extensive family of Caryophyllaceae. The genus Dianthus includes around 300 species of perennials, including the famous florist’s carnations, the pinks (Dianthus plumarius), and biennials like the renowned Dianthus barbatus or sweet William. Some new hybrid varieties of sweet William, such as the cultivars from the ‘Jolt’ series, combine vigorous growth, vibrant colours, great tolerance to heat and cold, and exceptional flowering from spring until frost.

Dianthus barbatus: botanical illustration from 1896

It is found in the wild at altitude on rocky slopes, in clear forests and meadows of Northern Europe and Asia. It is a fleeting perennial, perennial in climates with mild winters, but most often considered annual or biennial elsewhere.

From a branching stump, it slowly forms an upright, rounded tuft, 25 to 60 cm high with a similar spread. Dianthus barbatus is among the tallest of the carnations. The deciduous or semi-evergreen foliage consists of long, narrow, lanceolate leaves that taper to a point. This vigorous vegetation is coloured from light green to glaucous green.

The flowering emerges from these beautiful bushy tufts, from June to September. The plant flowers in the second year following its sowing.

The flowers are the true attraction of this herbaceous perennial. Sweet William offers a generous and slightly fragrant flowering. The floral stems bear large, dense clusters that bloom small, flat, solitary carnations tightly packed together. These terminal umbels can measure up to 15 cm in diameter. As with all carnations, the flowers can be single with 5 petals, double, or semi-double depending on the varieties. Their petals are delicately carved and fringed. They are encased in a tubular calyx and surrounded by elongated, narrow bracts, “barbatus”, referring to this frill.

Sometimes solid, often bicoloured, they display a combination of tones, variegated, maculate, or striated around a contrasting heart. Some varieties exhibit changing colours as they bloom. They come in an infinite combination of shades from white, mauve, pink, purple, red, or even anise green in the very surprising Dianthus barbatus ‘Green Trick’.

The colours of sweet William vary from solid to bicoloured petals, from white to almost burgundy red

Their characteristic fragrance is delightful, both spicy and sweet, reminiscent of clove and cinnamon. Nectariferous, these fragrant bouquets are highly visited by foraging insects, particularly bees.

Once cut, the floral stems make beautiful fragrant summer bouquets that last more than two weeks in a vase.

After flowering, the flowers transform into capsules containing many very fine seeds that sometimes self-sow abundantly.

The petals are edible, and their peppery, pungent flavour enhances summer salads, sorbets, or fruit salads, adding a colourful touch.

Main varieties

Dianthus Jolt Pink

A brand new hybrid variety selected for its vigorous and ramified growth, vibrant colours, and excellent tolerance to heat and cold.

• Flowering time June to October
• Height at maturity 45 cm

See the full description

Dianthus barbatus Indian Carpet Mixed

This carnation is a dwarf variety with a compact habit. It is an ideal plant for window boxes and borders.

• Flowering time July to September
• Height at maturity 25 cm

See the full description

Sweet William Double Seed Mix - Dianthus barbatus

This selection is well-suited for mass planting and self-seeds abundantly.

• Flowering time July, August
• Height at maturity 45 cm

See the full description

Dianthus barbatus Mix

Ideal for cut flowers, this selection is well-suited for mass planting.

• Flowering time July, August
• Height at maturity 50 cm

See the full description

Planting Poet's Carnations

Where to Plant It?

The poet’s carnation is truly easy to grow in all our regions. It is a hardy plant that withstands frost down to -10°C. It tolerates both rain and summer droughts.

It thrives in any fresh, rich, well-drained soil, even calcareous, preferably in full sun, although it will accept partial shade. It enjoys bright, warm locations and needs at least 3 to 4 hours of sunlight per day.

Plant it in groups along a pathway, near a frequently visited area, or in the middle of a sunny border to add splashes of colour. In the vegetable garden, it will also find its place in the corner reserved for cut flowers for bouquets.

It is particularly well-suited for window boxes on the terrace or balcony or on flowering slopes.

Dianthus barbatus in a border (© Leonora Enking)

When to Plant Dianthus Barbatus?

The planting of our poet’s carnation young plants in plug plants takes place in spring, from March to May, outside of frost and heavy rain periods.

How to Plant It?

In Open Ground

Count 5 to 9 plants per m². Ensure that the soil is well-drained, as waterlogged soil makes the carnation more vulnerable to rust or certain viruses. It does not fear summer drought but is wary of humidity, both in summer and winter.

• Work the soil to a depth of about twenty centimetres
• If necessary, incorporate gravel to improve drainage
• Plant in a mixture of potting soil and garden soil without burying the basal leaves
• Space the plants 20-30 cm apart when planting
• Fill in with soil
• Lightly firm down
• Water regularly to ensure good establishment

A dense planting ensures a very beautiful effect in the flower beds

In Pots

• Place a layer of clay balls or gravel at the bottom of the container to prevent standing water
• Plant in a mixture of potting soil, garden soil, and a bit of river sand
• Do not allow water to stand in the saucers
• Water and ensure that the substrate never dries out completely between waterings

Sowing of the carnation

Sow sweet William seeds indoors or in a greenhouse, from January to February, or directly in place, broadcast, at the end of spring or in summer for flowering in the following spring.

• Sow the seeds on the surface of good potting compost mixed with river sand
• Cover them lightly
• Place your seedlings in a mini-greenhouse at a temperature of 15-20 °C, or wrap the tray in a clear polyethylene bag
• Water with a fine spray without saturating the substrate until germination, which takes between 7 and 21 days
• When the seedlings have two or three leaves, transplant into 8 cm pots
• Allow the young plants to develop in cooler conditions
• Transplant outdoors, in the garden or in pots, when all risk of frost has passed

Maintenance and Care

Once well established, the beard pink requires little care. In summer, provide watering only during prolonged dry spells. Remove faded flowers as they occur to encourage the appearance of new flower buds.

At the end of the season, lightly cut back the clumps to 20 cm above the soil to prolong their life and ensure flowering the following year. Mulch at the base to protect the roots from the cold.

In pots or containers, apply fertiliser for flowering plants during growth.

Diseases and potential pests

The poet’s eye is relatively sensitive to certain pests and diseases such as the carnation fly, the tortrix, aphids, thrips, botrytis, rust, and alternaria. Grown in well-drained soil, it will be less vulnerable. To protect it, spray regularly with diluted 20% horsetail manure and 5% tansy manure.

Multiplication

The Dianthus barbatus is easily propagated from seeds. Propagation by cuttings in summer is another easy method to multiply all carnations.

→ Discover our advice sheet to succeed in your propagation by cuttings: “Propagate and sow carnations”

Associate

The Dianthus barbatus easily finds its place in both ornamental gardens and flowering pots, as well as in the vegetable garden in the cutting corner. Poet’s carnations are plants commonly found in vicarage gardens, ideal for creating an English-style border, where they blend perfectly with garden Columbines, Catmints, Scabious, Cleomes, Love-in-a-Mist, Phlox, and hardy geraniums.

They pair well with summer-flowering plants with large blooms such as Dahlias and Echinaceas. Accent the scene with small ornamental grasses (Carex, Stipa pennata) to add extra lightness. With their rich hues in endless shades, ruby red and pink, they spontaneously mix with the cool tones of Wormwoods or Garden Campions. In pots, pair them with moss Phlox or Aubrietas.

Dianthus barbatus alongside Love-in-a-Mist, Phlox paniculata, Cleomes, and Catmints

→ For even more inspiration, check out our advice sheet: “Carnations – 6 Pairing Ideas”