Thanks to innovative Dianthus breeding and marketing, one of Europe’s oldest cultivated ornamentals has staged a comeback as the newest kid on the block. What lies behind the modern pot carnation’s storming of the industry over the last ten years? And what might the future hold for this grower-friendly, seductive product?
Native to the northern Mediterranean, the perennial border carnation (Dianthus caryophyllus) has been improved and selected by breeders for at least 500 years, but not until the 1970s were systematic efforts made to develop dwarf strains for the pot plant market in the US, Japan, and Europe.
Over recent decades, huge strides in interspecific breeding programmes (involving, e.g. D. barbatus and D. chinensis) have reinvented the pot carnation as a product that is as attractive to producers and retailers (for its predictability, low energy costs, and shelf-life) as to consumers (for vivid colours and long flowering). Trading volumes tell their own story: in 2022, Royal FloraHolland traded 21.6 million units, mainly to Germany, followed by France and the UK, as well as the Netherlands.
A production process that allows for tight control of quality is key to the success of the modern pot carnation. Breeders such as Selecta One and HilverdaFlorist produce their cuttings in East Africa, where high insolation, cold nights and low humidity make for ideal growing conditions. Cuttings are then flown to rooting facilities in Europe before being sold to growers as rooted cuttings; at this point, most varieties can be grown without additional heat.
A significant driver in the huge expansion of the pot carnation market was producers’ realisation that empty frost-free glasshouses could be used to grow a valuable crop with little input. The growing season is long: European producers can meet Valentine’s Day demand with early varieties such as Selecta’s ‘I♥U’, ‘Early Love’ and ‘Purple Wedding’, and plants are offered for sale until late October (weeks 8-42). Under ideal conditions and depending on variety, smaller pot carnations can be finished in as little as ten weeks.
Pot carnations vary in vigour and habit, from super-compact indoor varieties to highly vigorous types for outdoor pots, such as Selecta’s Capitán series.
A key development in the modern carnation industry was Selecta’s compact Oscar series—a sport-based series based on colour mutations selected from the same parent. The extreme homogeneity of the varieties in sport-based series simplifies and streamlines production and opens creative possibilities, such as combining different colours in the same pot.
HilverdaFlorist offers four brands suitable for every market and cultivation programme: Beauties®, Flow®, Odessa® and Sunflor®. Each has its specific features and characteristics. HilverdaFlorist’s Sunflor® was one of the first pot carnation series on the market. Since its merger with HilverdaKooij and Florist Holland in 2019, the company has worked to rationalise its carnation portfolio. One important development has been the creation of a distinct grouping within the Sunflor® brand, Sunflor® Selection, which groups together varieties chosen for uniformity and speed.
HilverdaFlorist also has its Odessa® series that offers extra tall varieties. This series consists of voluminous and floriferous plants with vigour and frilly flowers. Odessa® varieties can be handled in larger pot sizes and can grow up to 30 cm.
The company’s Dianthus® Beauties series comprises perennial Dianthus varieties which are easy to cultivate indoors with limited heat or even outdoors throughout autumn and winter.
“Fast, compact, and rich flowering. “Beauties® is our perennial Dianthus series, which delivers an excellent garden performance with great flower quality and cold- and rain resistance. Several varieties produce a delicate scent. These tough perennials are easy to grow, quick to finish and programmable for year-round sales,” says HilverdaFlorist’s Sjaak Sijm.
While larger carnation varieties suitable for bigger pot sizes (e.g. HilverdaFlorist’s Flow or Selecta’s SuperTrouper) remain popular, particularly in warmer regions, the modern success of the pot carnation lies largely in its compact aspects—robust and easily handled in distribution, highly adaptable in retail programmes.
Popular sizes in Northern Europe are typically 10.5cm or similar (80 per cent of the 6 million Pink Kisses grown annually by IJzelenberg plant nursery in Westland, Netherlands, are in 10.5cm pots).
The aim of pot and container use is always to produce a well-branched, sturdy, compact plant. Specific growing strategies vary according to cultivar and local conditions, but plants always require good light and prefer to grow cool and dry. Cool nights help to build compact plants, avoiding the need for plant growth regulators.
The evolving regulatory landscape continues to make demands on growers. The use of PGRs is increasingly restricted and seems likely to be phased out completely (at least for European production). The gradual phasing out of reliable and predictable peat substrates is another challenge, particularly with a water-sensitive crop.
The reinvention of pot carnations as a distinctively modern product is seen in Selecta’s Gen Z-flavoured marketing programme for the Pink Kisses variety, its first campaign to target consumers directly.
Beginning in 2017, this innovative campaign has deployed emotion-based marketing techniques to target a younger demographic using social and influencing platforms.
Richard Petri, marketing consultant and carnation expert, sees scope for much greater use of B2C marketing, noting that carnations’ long retail window opens up unique possibilities. “Consumer marketing with most retail plants is very hard,” says Petri, “because the window to establish brand awareness is so narrow—only 6-8 weeks for bedding or poinsettias. Then, the season’s over, and you have to start all over again next year.”
But carnation can be finished and sold for eight months of the year, giving plenty of time for a campaign to bed in. Continual advances in breeding look set to provide marketers plenty to work with in the future: besides extending the colour range and selecting for scent, novelties such as the striking YTT-style colour shifts in Pac Elsner’s distinctive ‘Solo Con Te’ and Selecta’s ‘I♥U’ indicate that there is still much that remains to be achieved in carnation genetics.
This article was first published in the October 2023 edition of FloraCulture International