Sweet William – planting, care and tips

Sweet William (Dianthus barbatus)
Sweet William (Dianthus barbatus)

“Divine flower” – this is roughly how the botanical name of Dianthus barbatus can be translated. This name is no coincidence, because standing in full bloom, sweet William even outstrip roses as “Queen of Flowers”. The robust summer flowers have already played their charm in old cotton gardens. Their popularity led to the fact that the carnation family is now available in numerous cultured variations in specialist shops. In addition to different heights, plants with simple or double flowers are also available. But also the color spectrum of the different types is extremely versatile.

Profile of sweet William:

Scientific name: Dianthus barbatus

Plant family: pinks / carnation family (Caryophyllaceae)

Other names: sweetwilliam, bearded pink

Sowing time: Annual plants: February to April; Biennial: end of May to beginning of June

Flowering period: June to August

Location: sunny

Soil quality: sandy to loamy, calcipholous, nutritious, humus rich

These information are for temperate climate!

Use in: flower beds, bouquets, borders, group planting, planters, borders, cottage garden, flower garden, potted garden

Winter hardiness: hardy up to -32 °C/-25 °F

Bee and insect friendly: yes

Plant characteristics and classification of sweet William

Plant order, origin and occurrence of sweet William

Sweet William originally comes from the mountains of Southern Europe. Since the early Middle Ages, however, they can also be found in many gardens. From a botanical point of view, Dianthus barbatus belongs to the genus of carnations within the family of the carnation family (Caryophyllaceae).

Characteristics of sweet William


Carnations can be cultivated as annual and biennial plants. They grow to a height of between 10 and 70 centimeters (4 and 28 in).


The characteristic, silvery leaves are broad-leaved and soft. They are arranged opposite each other on the shoots.


The blossom peduncles reach heights of up to 60 centimeters (24 in), at the end a flat inflorescence develops with many individual flowers that spread a delicate fragrance. The colors and patterns of the flowers are more varied than with any other type of carnation. The color spectrum ranges from white to pink to red and an almost black scarlet tone. The flowers can be single-colored, but can also be spotted, striped or edged.

Each inflorescence has a tubular base of overgrown sepals. Simple blossoms have five petals, at double blossoms the number of petals is significantly higher: Up to 60 densely packed petals can be formed. The edges of the individual petals are fringed.


After flowering, capsules form in which are numerous seeds.

Sweet William flowering
Sweet William flowering

Sweet William – cultivation and care


The bushy growing plants need full sun to form their lush bloom. Even in the light partial shade, the growth of the plant suffers and its resistance to diseases and pests decreases. Sweet William can also be cultivated in the planter on the balcony or terrace. Here, too, the plants need direct and long-lasting sun exposure.


The substrate should meet the following conditions:

  • rich in humus
  • permeable to water
  • a slightly alkaline pH-value

The soil should be fresh and rich in nutrients, and good permeability is important to prevent waterlogging. A loamy, sandy garden floor is ideal for the carnation, a high proportion of lime in the ground is just what you need.

Sowing / Planting

Annual sweet Williams can be sown from February to April. Two to three seeds are planted per pot. Potting compost is suitable as a substrate, the temperature should be 15 to 20 °C / 59 to 68 °F. After about a month, the temperature is lowered to 12 to 14 °C / 54 to 57 °F. The young plants can then be relocated to the field in mid-May, the planting distance should be 20 to 25 centimeters (8 to 10 in). Biennial sweet Williams are sown in the bed from the end of May to the beginning of June, the temperature for this should be 15 °C / 59 °F. It is important not to plant too late, as the plants die off from frost more easily if they are not sufficiently rooted.

Propagation by division is also possible with biennial plants, but is only worthwhile for particularly beautiful specimens.


It is advisable to water sweet William moderately during growth, but waterlogging should be avoided.


When cultivating on very poor soils, it may be advisable to apply some universal fertilizer in spring. However, attention is required here, as sweet William do not tolerate over-fertilization.


Sweet William rarely get older than 2 years and can be completely disposed of on the compost after the last flowering. However, you can extend the flowering time of the plants with a simple measure: To do this, cut off all shoots directly above the ground immediately after the flowering period has ended. As a result, the flower will bloom again in late summer. However, this splendor is considerably less than the first bloom in early summer. Prevent the plants from self-seeding by immediately breaking off or pruning dead plant parts. However, it is not uncommon for some plants to appear unexpectedly on the compost if you disposed of the cut flowers there. Dianthus barbatus is also suitable as a cut flower. In order to enjoy the colorful flowers for a longer time, there are a few tips to keep in mind:

  • Use only well-sharpened scissors or knives for the cut
  • Cut early in the morning, the flowers are still in full juice and therefore last longer
  • Use only well-cleaned vases
  • Shorten the end of the stem by a few centimeters (1 in) every 2 to 3 days
  • In the direct vicinity of fruits and vegetables, the cut flowers wither faster

Diseases and pests

Sweet William is at risk from an infestation of various pests and plant diseases. These include aphids, spider mites, stem nematode, thrips, leaf spot disease and wilting diseases. Even from typical carnation diseases like the carnation rust or the carnation blackness, sweet William are not safe. Infestation with various viral diseases can also occur. Many problems that arise can be traced back to damp floors and can be prevented by installing a suitable drainage.


In frost, you should cover the sweet William with a winter protection made of spruce twigs.

Use in the garden

Sweet Williams are particularly appealing when planted in groups. They are suitable for various purposes and look just as good in the foreground of beds with perennials or assorted borders as a flowering edging. Sweet William can also be cultivated as container plants. Since they are very easy to cut, they expand the range of cut flowers from one’s own garden. Combinations of differently colored flowers look great in the vase. Suitable planting partners in the bed include baby’s breath (Gypsophila) and snapdragons (Antirrhinum). When choosing the neighbor-plants, it is particularly important that they do not take the light from the sun-loving plant.

Be the first to comment

Leave a Reply

Your email address will not be published.