Summary:

In 2002 the nurseries associated in Polish Nurserymen Association offered 4597 species and cultivars of woody plants and perennials, whereas 14 years later the number of available plants increased to 6361 taxa. During this time 1781 new species and cultivars were introduced and this means that every year 162 new taxa appeared on the market. During this period of time the number of climbers offered to gardeners was doubled, also number of conifers and broad leaved plants increased significantly, respectively 57,6 % and 48,2 %. However, with respect to the range of products and still increasing list of species, Polish nurserymen offer twice fewer plants than their colleagues from Holland or Germany. Import of new species and cultivars is the main source of plants so far unknown in Poland. Results of presented studies show that the number of holdings which import new plants from abroad increases proportionally to the expanding area of nursery production. The import of new species poses risk for the local environment and landscape, particularly the rural areas, because some of the foreign species are known as invasive. Results of the survey questionnaire show that theissues of invasive alien species are quite well known in the nurserymen's circles. Above half of questioned producers are aware of what this risk involves. However, this knowledge is positively correlated with the growers' education. This issue is a bit less obvious when individual invasive alien species must be named or when this kind of information should be transferred to the customers purchasing the plants.