Germany's Inkarho GmbH, the interest group for lime-tolerant rhododendrons based in the Ammerland region of Lower Saxony, celebrated its 25th anniversary on 15 March 2026. To mark the occasion, 28 shareholders, licensees and close industry associates gathered at the propagation nursery Schröder Rhododendron in the Ammerland.
The anniversary also provided an opportunity to recognise outstanding contributions. Bernd Schmidt (Bruns Pflanzen), who co-founded the organisation together with Diderk Heinje and initially led it on a voluntary basis, was honoured alongside Werner Borchers (Borchers Baumschulen), who took over that role in 2008. Borchers handed over responsibility in 2025 to Frank Meinen (Baumschule Hans Meinen), who now leads the organisation on a voluntary basis alongside co-founder Diderk Heinje, supported by advisory board chair Jan Hinrichs (Hinrichs Pflanzen). Continuity is further ensured by Ralf Lüttmann, who has held the position of managing director as a permanent employee for 25 years.
© Inkarho
Inkarho traces its origins to a concept aimed at enabling rhododendrons to thrive in calcareous soils without the addition of peat. Decades of breeding work produced numerous crosses. More than two million seedlings were tested in vitro, subsequently evaluated in field trials and subjected to rigorous selection. From approximately 600 promising plants, 60 elite clones emerged, distinguished by strong root development in lime-rich soils and their suitability as rootstocks.
The establishment of Inkarho GmbH & Co. KG in 1992 marked a decisive step: the best elite clones could be acquired from the Federal Research Institute. Following further trials at participating nurseries and at the LVG Bad Zwischenahn horticultural research station, the lime-tolerant rootstocks were officially introduced to the market in 1997, including the filing of variety protection applications. In 2001, the current Inkarho GmbH was formally founded by 16 nursery growers with the aim of bringing the jointly developed lime-tolerant rhododendron varieties to market.
Over the years, Inkarho has built a broad portfolio of rhododendrons grafted onto specialist lime-tolerant rootstocks. The organisation gained widespread recognition through Bloombux, a lime-tolerant cross between Rhododendron hirsutum and Rhododendron micranthum, available in pink and magenta-red, with a white form in development. For low hedging and ground-cover applications, Nugget by Bloombux has been introduced.
Easydendron, available in more than 30 varieties, signals through its name that planting rhododendrons is now straightforward in virtually any garden. For hedging, the Inkarho-Dufthecke series offers cutting-propagated, particularly pruning-tolerant varieties in white, lilac, pink and yellow.
With Happydendron, Inkarho has deliberately taken a new direction: the colourful, contemporary presentation of the variety 'Pushy Purple' is aimed at a younger audience, with the goal of giving rhododendrons a modern image. The newest product line, Grazeasy, crosses with Rhododendron ponticum 'Graziella', rounds out the range, notable for their narrow foliage, striking red new growth and flowers in deep pink, violet or light pink. Further introductions, including an additional Happydendron variety, are already in development.
Through its variety portfolio and active marketing, Inkarho has developed a growing international presence. Licensees from France, Japan and Canada are among the 18 licensing partners currently working with the organisation. The programme has received multiple industry accolades, including the German Horticultural Innovation Award and several TASPO Awards.
Despite an overall contraction in the rhododendron market, Inkarho has maintained stable sales figures. Annual sales amount to approximately 600,000 Bloombux plants and a further 150,000 plants from other Inkarho brands. In parallel, the organisation has been collaborating for several years with breeder Frank Schnupper on new product lines, with a number of promising clones already in the trial phase ahead of potential market introduction.
Twenty-five years after its founding, Inkarho GmbH can look back on a successful development, and looks ahead to coming years with confidence, together with its shareholders and licensing partners.
For more information:
Inkarho
https://www.inkarho.de/nl/
