Carnation

Dianthus caryophyllus

1. Identification and origin

The carnation (Dianthus caryophyllus L.) is a perennial species of the family Caryophyllaceae, native to the Mediterranean region. It is widely grown as an ornamental plant, especially as a cut flower, being one of the most marketed flowers worldwide. There are numerous cultivars selected for colour, flower shape, resistance and post-harvest longevity.

2. Economic importance

The carnation is a crop of high importance in floriculture, especially in greenhouses. It is valued for its diversity of colours, good vase longevity and strong presence in the international cut-flower market. It has economic relevance in Mediterranean countries, including Portugal, where it is grown in greenhouses and in the open air.

3. Botanical characterization

A perennial herbaceous plant, of erect habit, with knotty stems and linear, opposite and glaucous leaves. The flowers are solitary or grouped, with fringed and highly fragrant petals. The fruit is a capsule containing numerous small seeds. The root system is fibrous, sensitive to waterlogging and compacted soils.

4. Soil and climate requirements

It prefers temperate climates, with optimal temperatures between 12–20 °C. It is sensitive to excessive heat and high humidity, which favour fungal diseases. It develops best in well-drained, slightly alkaline soils (pH 6.5–7.5), rich in organic matter. It requires good light and ventilation, especially in greenhouses.

5. Main pests

• Whitefly (Bemisia tabaci, Trialeurodes vaporariorum): sap sucking and transmission of viral diseases.
• Aphids (Aphididae): leaf deformations and transmission of viral diseases.
• Thrips (Frankliniella occidentalis): damage to petals and commercial devaluation.
• Mites (Tetranychidae): chloroses and loss of vigour.
• Nematodes (Meloidogyne spp.): root galls and plant decline.

6. Main diseases

• Fusarium wilt (Fusarium oxysporum f. sp. dianthi): vascular wilting and plant death.
• Rust (Uromyces dianthi): orange pustules on leaves and stems.
• Septoria leaf spot (Septoria dianthi): necrotic leaf spots.
• Botrytis (Botrytis cinerea): grey rot on flowers and young tissues.
• Carnation mosaic virus (CarMV): mosaics and reduction in flower quality.

7. General crop management

Management includes the use of certified plants, well-drained substrates and adequate ventilation in the greenhouse. Irrigation must be controlled to avoid waterlogging and reduce the risk of fusarium wilt and Botrytis. Monitoring of thrips, aphids and whitefly is essential to prevent viral diseases. Harvesting must be carried out at the coloured-bud stage or beginning of opening, according to the market.

Bibliographic references

• EPPO Global Database – Dianthus caryophyllus.
• CABI Crop Compendium – Dianthus caryophyllus.
• Bailey, D. A., & Whipker, B. E. (2015). Floriculture: Principles and Species. Prentice Hall.
• Byrne, T. G. (1999). Carnation production. In: Cut Flowers and Foliage Production. CABI Publishing.
• FAO (2010). Cut flower production guidelines – Dianthus spp. FAO Plant Production and Protection Division.