Carnation treatments, most common diseases and pests of this flower

carnation dianthus caryophyllus

carnation dianthus caryophyllus
The carnations are a plant species which blooms annually, twice a year or year-round. The carnation has pointy, lanceolate, a green to gray color, positioned alongside the stem leaves; the leaves also slightly bend towards the outer side.

The flowers can be pleasant smelling, simple or double, brightly colored. There are a lot of carnation hybrids which do not have a smell, but they can have a large variety of colors.

The carnations often bloom during the cold seasons, mostly at the beginning of winter. These flowers are perfect garden flowers, but also, they look great as vase flowers. If the carnations are well taken care of, they can live up to one month in flowerpots.

The carnations originated from Eurasia and are the most popular garden flowers, a part of the 300 annual, bi-annual perennial Dianthus plant species. There are hundreds of types and hybrids. In Greek, “dianthus” means “flower of Zeus” or “divine flower”.

The carnations can grow up to 60-90 cm long, although most garden species only reach 25-50 cm.

Planting and taking care of the carnations

The carnations are very popular flowers, both commercially and ornamentally.

The carnations could be well used as sideways decorative plants, in rock/pebble decorated gardens and even in flower pots. The carnations grow in a large variety of colors, such as, red, brick-red, orange, violet, yellow, pink, white, cream-colored.

The carnations require a fertile soild, slightly alkaline or neutral from a pH point of view, easily drainable, with at least 4-5 hours of sun per day.

The soil must be moist. Avoid over-watering the plants because it can lead to the foliage turning yellow. To have to carnations bloom constantly, they must be treated with a liquid fertilizing solution (10-10-10), every 6-8 weeks.

The wilted flowers must be removed in order to encourage continuous blooming.

Main diseases 

Fairy-ring Leaf Spot is produced by the Mycosphaerella dianthi fungus. The disease is visible on all the plant’s organs, where round or oval spots, yellow to brown in color, with a red or violet margin, grow. On the surface of the spots a brown to black, dusty looking mold grows, which represents the fungus’ sporulation. The affected flowers no longer open or they grow irregularly.

Prevention and control measures:

  • Avoid excess watering and periodically air the greenhouse  
  • Gathering and burning the plants which have been severely attacked
  • Plant healthy treatments using Topsin 70 WDG (10 g/ 10 l water), Teldor 500 SC (7 ml/ 10 l water), Rovral 500 SC (10 ml/ 10 l water).

Carnation Rust is caused by the Uromyces caryophyllinus fungus. The disease attacks the leaves and stems. The affected plants have yellow leaves and on both sides of the yellow leaves the fungus’ uredospore grow, which are oval, brown and limited by the torn apart epidermis. The affected plants have thin stems, do not bloom or if they do, the flowers are bleached.
carnation dianthus caryophyllus carnation rust
Prevention and control measures:

  • Gathering and destroying the affected parts of the plants
  • Avoid excess moisture in the crop
  • Plant health treatments using Bumper 250 EC (20 ml/ 10 l water), Polyram (20 g/ 10 l water), Dithane M 45 (20 g/ 10 l water), Topas 250 EC (5 ml/ 10 l water).

Dianthus Leaf Spot is caused by the Septoria dianthi fungus. The disease attacks the leaves, stems and the flowers. On the affected organs, circular or irregularly shaped spots, white to gray colored spots, narrowed by red to violet edge, appear. This disease affected both greenhouse plants and crop plants. The affected plants have dried-up base leaves, with a wrinkled and twisted look.
carnation dianthus caryophyllus dianthus leaf spotcarnation dianthus caryophyllus dianthus leaf spot 1
Prevention and control measures:

  • Using healthy cuttings
  • Gathering and destroying the plants which have been severely attacked
  • Plant health treatments using Topsin 70 WDG (10 g/ 10 l water), Merpan 50 WP (20 g/ 10 l water), Mirage 45 EC (35 g/ 10 l water), Falcon 460 EC (20 ml/ 10 l water).

Carnation Blight is caused by the Alternaria dianthi fungus. The disease attacks the leaves, the stems and the flowers. The affected organs have circular, gray to white spots, of 10-15 mm diameter, covered by a black mold in the center. The affected leaves gradually wilt from the base towards the edges and on the stems injuries form which surround the stems like a ring. As a result of the attack, the stems break. The plants which have been severely affected have shorter internodes and bloom less.
carnation dianthus caryophyllus carnation blight
Prevention and control measures:

  • Avoid excess moisture inside the plant’s growing places
  • Using healthy cuttings
  • Plant health treatments using Antracol 70 WP (20 g/ 10 l water), Bravo 500 SC (20 ml/ 10 l water), Merpan 50 WP (20 g/ 10 l water), Dithane M45 (20 g/ 10 l water).

Fusarium oxysporum f.sp dianthi in Carnations is caused by the Fusarium oxysporum f.sp dianthi fungus. The symptoms are the leaves gradually wilting and turning yellow. At the base of the stem, the tissues are brown and destroyed. As a result of the attack, the stems easily break. If the stems are sectioned on the affected areas the veins will look completely brown or will have longitudinal brown stripes. The affected roots are either brown or red. On the rotten tissues, especially on the base of the stem, the fungus grows a cotton like mycelium where the sporulation can be differentiated.
carnation dianthus caryophyllus fusarium oxysporum in carnationscarnation dianthus caryophyllus fusarium oxysporum in carnations 1
Prevention and control measures:

  • Using only healthy cuttings
  • Gathering and destroying the affected plants
  • Plant health treatments using Dithane M45 (20 g/ 10 l water), Topsin70 WDG (10 g/ 10 l water), Falcon 460 EC (25 ml/ 10 l water), Zamir 40 EW (25 ml/ 10 l water)

Gray Mold disease caused by the Botrytis cinereal fungus. The disease mostly attacks the flowers. Rapidly extending and turning brown spots grow on the flowers. On the surface of the affected tissues, the gray sporulation, which is characteristic to this fungus, grows.
carnation dianthus caryophyllus grey mold

Prevention and control measures:

  • Gathering and destroying the affected leaves and flowers
  • Plant health treatments using Teldor 500 SC (7 ml/ 10 l water), Rovral (10 ml/ 10 l water), Topsin 70 WDG (10 g/ 10 l water), Ridomil Gold MZ (25 g/ 10 l water)

Pests

Aphids, for which the following pesticides are recommended: Calypso 480 SC (2 ml/ 10 l water), Decis Mega (3 ml/ 10 l water), Karate Zeon (2 ml/ 10 l water), Fastac (2 ml/ 10 l water).
carnation dianthus caryophyllus aphids 1

Acari, for which the following pesticides are recommended: Envidor 240 SC (5 ml/ 10 l water), Nissorun (5 g/ 10 l water), Milbeknock (7.5 ml/ 10 l water).

Thrips, for which the following pesticides are recommended: Confidor Energy (25 ml/ 10 l water), Novadim Progress (20 ml/ 10 l water).
carnation dianthus caryophyllus thrips

 

Got a question?

  1. Carnations were blooming profusely but have not seemed to thrive. Height has not increased and they have stopped blooming. There were lots of buds but now it looks as if the inside of the buds have been eaten I dug one up and the roots have not made any growth. I have fertilized and watered with care. Any idea please? Pinks planted at the same time in a different area have thrived the problem is how to displat the blooms.

    Brian Burton -
    Answer
    1. Can you tell us if you saw any pest inside the buds (because you said that’the inside of the buds have been eaten’)? Also, they are in pots or in the garden?

      Nexles -
      Answer
  2. I have 8 dianthus planted in the four corners of 2 beds. Six are beautiful and full. Two have stems that have turned brown on one side of the plant and basically pull out of the ground. What can cause this?

    Alexis Avis -
    Answer
    1. It may be a soil problem, or there is a higher humidity in that area.

      Nexles -
      Answer
  3. My pink carnations are full of tiny black beetles. When you look into the heart of the flower it is black with these horrible tiny black bugs.

    Gabrielle Page -
    Answer
    1. You could apply a broad-spectrum insecticide, that is friendly to bees, like Calypso.

      Nexles -
      Answer
  4. My pot carnations are overwatered, I think. Because they are a kind of wilted, I guess. What should I do to prevent them from dying? Thanks

    Perka -
    Answer
    1. Be careful with the volume of water administered and let the substrate dry up between waterings. It is recommended to apply fertilizer to help regenerate the plant, such as Biplantole Vital, applied by watering in a dose of 2 ml / 1 l of water. Then, after 10-12 days, you can apply again Biplantole Vital, this time applied foliar by spraying, in a dose of 20 ml / 1 l of water. Foliar applications can be repeated every two weeks in the spring-autumn period.

      Nexles -
      Answer
  5. I have lots of lovely blooms on my pinks, but lately all the flower are partially brown even when the bud first starts to come out. Is it a pest?

    Emma Eaves -
    Answer
    1. Thank you for your request. Please give us the details we have requested in email.

      Nexles -
      Answer
  6. One of my potted pinks is falling over (not wilting). When I looked at it today I found earwigs under the pot and one hanging out in a flower. What should I do?

    Lauren -
    Answer
    1. Thank you for your request. Please provide the details we have requested by email, so we can follow up with a relevant treatment option.

      Nexles -
      Answer
  7. I’ve discovered recently that my Dianthus barbatus buds keep being munched before they bloom. Some of the buds have holes and are completely hollow. Others the top point are simply munched (from something tiny). I don’t know what it could be and I want them to grow so badly.

    Madelaine -
    Answer
    1. Thank you for your request. Please provide the details we have requested by email to follow up with a relevant treatment option.

      Nexles -
      Answer

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