Preschool gardens have an important role in the children's life, in the development of their self-awareness at early age, in developing work and healthy eating habits as well as in the environmental awareness development. The transformation of the previous rural area across-the-Sava, southwest of Zagreb, into one of today's city districts began only half a century ago. A part of the city district has been planned and built in compliance with the urban planning style, while the other part of the style reveals its rural character. In the whole area of Novi Zagreb (East and West), there are 10 urban and 9 private kindergardens. The objectives of this thesis are to ascertain the existence of the gardens with preschool establishments in city district Novi Zagreb. The aim is also to determine garden's size and function, to make an inventory of dendrologic flora, to determine the taxonomic affiliation, the origin and invasiveness, analyze the presence of toxic and allergenic plant species, to evaluate the arrangement of the gardens and to propose the plant species. Furthermore, the objective is also to improve the ways of application and the activities for the children education improvement in the basics of gardening at educational institutions. In the period from March till end of May 2019, frequency of poisonous and allergenic plant species on locations of preschool institutions in the city district Novi Zagreb in Zagreb. Ten locations were included in the research. In the gardens of Novi Zagreb – east were found 49 species of trees and 18 species of bushes and climbers plants from a total of 23 families, and in the gardens of Novi Zagreb - west were also determined 49 species of trees and 24 species of bushes and climbers plant from a total of 26 families. In the gardens of Novi Zagreb – east, there were 26 of poisonous plant species with 190 specimens (52%) and 36 allergenic plant spacies with 280 specimens (77%). In the gardens of Novi Zagreb – west, 30 of poisonous plant species with 163 specimens and 430 m of 'poisonous' live hedges (79%) and 42 allergenic plant spacies were found with 224 specimens and 592 m of 'allergenic' live hedges (89%). One of the main stages in the landscaping design is a selection of plants for decorating green areas. Some species, besides their aesthetic purpose, can have harmful effect which has to be taken in consideration. Plants that are not toxic, allergenic or thorny should have the priority at decorating school and kindergarden yards. Decorating and landscaping are in the second place in that case.