'Tree fertilizer' is an English equivalent of 'fertilizante para árvores'.
The Portuguese word 'fertilizante' is a masculine noun. Its singular definite article is 'o' ['the'], and its singular indefinite article 'um' ['a, one']. The preposition 'para' means 'for'. The feminine noun 'árvores'means 'trees'. Its plural definite article is 'as', and its plural indefinite article 'umas' ['some'].
All together, they're pronounced 'fuhr-tchee-lee-ZAHN-tchee PAH-ruh AHR-voo-reesh'.