Dianthus: How To Care For The Sweet William Flower

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Dianthus are perfect pot plants known as pinks or Sweet Williams – Dianthus barbarous.

They belong to the family of Caryophyllaceae (carnations) and have a peculiar spicy aroma when they bloom. Some believe the plant is named after William Shakespeare.

Dianthus Sweet William FlowersPin

Sweet Willam flowers are annual, biennial, or perennial plants grown mostly as pot plants for use in various borders. They have been proven to be one of the oldest cultivated plants.

While wild varieties of Dianthus plants are native to Northern Europe, South Africa, China, Asia, and Alaska regions of the world, these carnations have also been cultivated in greenhouses and used for wine flavoring in France and Spain.

The Dianthus Pinks have made many records.

  • They were the first and hence oldest plants cultivated in greenhouses.
  • They happen to be the first plants on which a book is written.

Sweet William flowers have fragrant flowers, dashing varieties which can grow from 20″ inches to 3′ feet tall plants. Their mounded structure produces flowers in clusters.

Dianthus Quick Care Tips

  • Botanical Name: Dianthus barbatus
  • Common Name(s): Sweet William
  • Synonyms: None
  • Pronunciation: Di-AN-Thus baar-bay-tuhs
  • Family & Origin: Caryophyllaceae family, native to Northern Europe, South Africa, China, Asia, and Alaska
  • Growability: Easy to grow
  • Grow Zone: 3-9
  • Size: 20″ inches to 3′ feet tall
  • Flowering: Blooms in late spring to early summer with clusters of small, fragrant flowers in shades of pink, red, white, and purple
  • Light: Full sun to partial shade
  • Humidity: Tolerates low humidity
  • Temperature: 50˚ to 72˚ degrees Fahrenheit
  • Soil: Fertile, alkaline, and well-drained soil
  • Water: Water regularly, but do not overwater. Allow soil to dry out slightly between waterings.
  • Fertilizer: Fertilize with slow-release fertilizer of 5-10-5 composition every 6 to 8 weeks
  • Pests & Diseases: Susceptible to aphids, slugs, and snails, and prone to root rot, crown rot, rust, and powdery mildew.
  • Propagation: Propagate by seed, cuttings, and division
  • Plant Uses: Great for borders, rock gardens, and containers. Attracts butterflies and hummingbirds. Can be used as a cut flower.

Sweet William Care

Growing and caring for these colorful plants of the Caryophyllaceae family is easy.

As we know, Dianthus barbatus Sweet William, also known as Dianthus barbatus, can be annual, perennial, or biennial.

There are several varieties in each category and over 300 varieties in total.

Size and Growth

The most popular annual variety of Dianthus plants is the Chinese pink, also called dianthus chinensis.

Hardy in zones 6-9, with proper care Dianthus Chinesis does great as a container plant. China pink usually live short lives, rarely surviving more than two years, making them more of a biennial than a perennial.

Perennial types include Cottage, Grass Pinks, and Cheddar, and these have a peculiarity in foliage color. The foliage is blue-gray in color for all these and sometimes also comes in a rainbow of colors.

The Sweet William flowers (Dianthus firewitch), once crowned as the perennial plant of the year, were discovered by a German horticulturist.

Many growers love fire witch flowers and the perennial plant itself, as they make a great border plant for zones 3-9. Its fringed petals appear deep pink and magenta, while exuding a lovely, fragrant scent like cloves.

Another perennial plant that gardeners love is the Dianthus superbus, also known as superb pink or fringe pink. Its flowers hold beautiful colors ranging from subtle pale pink to a lavish, deep lilac.

Dianthus kahori, or the maiden pink, is a hybrid dianthus flower that makes a tidy border plant. It grows in late spring, holds extended blooms, and is fairly easy to grow.

The Sweet William flower is bright, fragrant, reseeds itself, and is biennial in nature. Some double flowering varieties like Allwood Sweet William pinks develop in a range of 6″ – 18″ inches in height.

Flowering and Fragrance

These pink carnations are great additions to the summer gardens. They have a long bloom time from late spring to early summer and continue to bloom from March to October.

Being floriferous and vibrant in appearance, they make the best ornamental choices for a wall garden, rock garden, or simple borders where they attract butterflies and bees.

Light and Temperature

Sweet William grows well in cool climates. They should be planted in a spot where they receive full sun for at least 4-5 hours of the day.

Plants enjoy full sun, partial shade, or afternoon shade from the hot summer temperatures.

The ideal daytime temperatures range from 50˚ to 72˚ degrees Fahrenheit for best production and nighttime temperatures range between 40˚ and 60˚ degrees Fahrenheit.

Watering and Feeding

Sweet William plants cannot bear overwatering as it turns the foliage yellow. Watering once a week is just enough for Dianthus.

Good and continuous air circulation around the stems is essential for good growth.

Although the Sweet William Dianthus plants are drought tolerant, they must be watered if the rainfall has been less than 1″ inch per week.

However, excess water is also harmful to these plants as they are light feeders. It also doesn’t tolerate high humidity.

Fertilize the plants every 6 – 8 weeks for fulfilling their needs. A slow-release fertilizer of 5-10-5 composition is best suited for Dianthus Plants.

Soil and Transplanting

Using fertile, alkaline, and well-drained soil is suitable for growing these perennials.

Retention of moisture is essential for Sweet William Dianthus barbatus. For any plant, layering the soil with a thin layer of mulch facilitates retaining moisture. This also controls weeds and facilitates better air circulation.

They like rich soil that stays loose but drains well. Don’t pack the soil around them too firmly. 

Grooming and Maintenance

The stems should be kept upright for better blooming. Moreover, spent blooms must be removed as this helps them in re-blooming. Remove these with sharp, sterilized hand shears.

Pruning is another Dianthus care tip. The plants do not show any invasive behavior and hence, need to be pruned once in a while. Pruning helps the second season of blooming to start.

Deadheading of plants is necessary as the dead bloom prevents the next bloom to sprout. Natural compost should be worked in the soil for nourishment.

How To Propagate Dianthus Sweet William

Plant Sweet William Seeds

Spring is the best season for planting dianthus seeds. Start planting seeds indoors before the season’s last frost for them to bloom in spring.

The seeds can also be planted in soil with sunlight just before spring, so they will grow by summer.

  • Sweet William seedlings should not be planted very deep.
  • Plant them 1/8″ inches deep in easy-draining soil that is mildly alkaline (PH 6.75).
  • The soil should be laid firmly on these seeds and should be kept moist until the seeds sprout.
  • Seeds can be saved from an earlier batch for planting in the following seasons.
  • Plants from seeds do not flower until after one year.

Propagating Sweet Williams

The perennial Sweet William varieties can be grown from cuttings and division.

For this, you need soft cuttings of plants taken in the spring or summer, which can be planted in the fall. Plants grown from the cuttings do not flower until next year.

Dividing the established clumps is an easy way of propagating the Dianthus plants. This method also rejuvenates the older clumps which become nonproductive over time.

Like other perennial plants, using forks, you must remove the soil and take the old plant aside. Here you can plant the new cuttings and water them occasionally.

One more method of propagating is Tip Layering. Peg one tip from the growing stem can be planted in the ground, and the roots start to develop. This is when you need to separate it from the mother plant.

Sweet Willaim Plants Pests or Diseases

If you overwater the Dianthus plant, crown rot may occur, the same for other perennials.

Once this disease affects your plants, there exists a very low chance of survival.

The petals and the affected side of the plant will appear darker. Also, its foliage will turn to yellow, and death comes quickly after.

These plants are generally not susceptible to diseases, but once in a while, pests or aphids can definitely infect them. Slugs and snails enjoy munching on their leaves.

Control and kill the aphids and insects by treating them with biological insecticides, natural organic insecticidal soaps, or by using beneficial predatory insects.

This plant is also prone to root rot, crown rot, rust, and powdery mildew.

Suggested Sweet William Flower Uses 

With so many varieties and versatile nature, few plants can compete with the Sweet William Dianthus perennial.

This makes these plants the favorite pick of ornamental plants worldwide.

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