International Hardy Plant Union
Servatiusstra├če 53
D 53175 Bonn

Telephone: +49 228 81002 51
E-Mail: info@isu-perennials.org


The ISU was founded in Hannover on the 14th January 1965 by German, Dutch and Swiss nurserymen, with the idea of co-ordinating their interests on an international basis. From these early beginnings, the ISU has developed into an association of perennial plant growers and persons from related professions, with approx. 300 members in 16 European countries, as well as in the USA and Canada.

The ISU is the only worldwide association of perennial plant growers. It connects professionals and promotes contacts all over the world.

The purpose and objectives of the ISU

The primary aim of the ISU is to promote contacts among the perennial plant growers and users from different countries in the field of the cultivation, the assortments, the trade and the use of perennials.
The ISU also facilitates business connections. Thanks to the ISU young nurserymen find jobs abroad where they can make further professional studies. Another kind of contact could promote the development of product assortments in particular nurseries.

Review of the nomenclature

The ISU strives for a standard nomenclature of perennials. It monitors the work of the international nomenclature commission and formulates the interest of the perennial plant producers in questions of nomenclature. The aim of the ISU is an internationally recognised, unified nomenclature of perennials.

Promotion and co-ordination of perennial plant evaluation

The analysis commission keeps note of and co-ordinates analysis work in several European countries. Perennial plant assortments are planted out in experimental gardens in Germany, Netherlands, Austria, Belgium and Switzerland and examined for purity of the variety, range of uses and garden suitability. Plants marked with the same cultivar designation but from different origins will be in the test beds for at least three years, where their properties are regularly observed and noted.

The ISU offers its members

  • Every 2 year we organise the Summer Days as a real meeting point for all colleagues. During these days the General Assembly takes place
    Every two years, within the framework of the Congress, the ISU organizes excursions which include visits to members' nurseries. Also on offer are trips to botanical gardens, gardens and parks with outstanding perennial plant collections, places of botanical interest, etc. These Summer Days are very popular and provide an opportunity for exchanges of experience.
  • Botanical excursion
    The every two years botanic excursion weeks in European areas are also very popular. The emphasis is not on physical performance but on the opportunity to experience wild flora in its natural habitat.
  • Awards for newly introduced perennials
    Within the framework of the analysis conventions, the evaluation commission judges the registered new introductions and awards the best of them an ISU certificate. In this way the ISU hopes to contribute to the propagation of interesting new perennials.

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