This is the 5642nd most frequent Polish word.
wiosennych
"Of spring" or "spring-related."
Here, 'wiosennych' functions as an adjective in the genitive plural form, describing the type of crocuses (spring crocuses).
Kwiaty wiosennych krokusów zaczęły kwitnąć.
The flowers of the spring crocuses have started blooming.
In this sentence, 'wiosennych' is an adjective in the plural genitive form, describing the trees in the context of the season spring.
Lubię spacerować wśród wiosennych drzew w parku.
I enjoy walking among the spring trees in the park.
Here, 'wiosennych' is used as an adjective in the genitive plural form to describe the orchards related to the spring season.