CLONAL SELECTION OF HERBACEOUS PERENNIALS FOR NORTHERN URBAN AREAS

In Finland, woody plants and annual summer flowers have dominated the plant choices in landscaping of public areas. Along the extension of the urban environment, the economy and ecology of public green areas has received more attention. Perennial herbaceous species could offer economical low-maintenance alternatives and in addition, have a positive effect on the ecology of green areas. At Agrifood Research Finland MTT, Horticulture, a project aiming at an increasing use of perennials in urban landscaping was started in 2005. To investigate the diversity of several perennial herbaceous plants in Finland, clones of several genera or species were collected from nursery, botanical and private gardens for field trials. The field trials were set up in 2005 and 2006 in Piikkiö and Espoo, Southern Finland and in Ruukki, Northern Finland, and will continue until 2010. They consist of 380 clones of Aconitum, Aconogonon, Asarum, Aster, Astilbe, Astrantia, Campanula glomerata, Delphinium elatum, Dicentra, Doronicum, Eupatorium, Fallopia, Geum coccineum, Hosta, Iris, Monarda didyma, Nepeta, Salvia and Thymus. The genera were selected because of their potential in landscaping and because of confusions in their nomenclature in nurseries. Although these clones originate from remote locations, most of them have been in cultivation in Finland, some even for decades, and are thus to varying extent adjusted to the northern climate. The clonal selection of perennials aims at finding the healthiest and hardy clones for use in Finland and other northern areas. The selection of the clones with the highest quality is done by intensive monitoring of health, pests, covering, growth, phenology, over-wintering, flowering and ornamental value. One of the main aims of the project is also to taxonomically identify clones within a genus and to clarify the nomenclature. For this purpose, DNA-fingerprinting has been introduced in the perennial research and will be applied in the near future.