U radu je istraživan utjecaj kultivara i tipa reznice na postotak ukorjenjivanja i duljinu korijena reznica američke tuje (Thuja occidentalis). U pokus su bili uključeni kultivari 'Columna' i 'Smaragd' u kombinaciji s tri tipa reznice tj. jednostavne reznice, reznice s petom te reznice s dijelom grane. Postotak ukorjenjivanja reznica bio je pod značajnim utjecajem kultivara i tipa reznice, dok je duljina korijena bila pod značajnim utjecajem tipa reznice. Kod kultivara 'Smaragd' zabilježen je veći prosječni postotak ukorjenjivanja nego kod kultivara 'Columna'. Veći postotak ukorjenjivanja zabilježen je kod oba kultivara uz upotrebu reznica s dijelom grane i jednostavnih reznica, u usporedbi s reznicama s petom. Prosječna duljina korijena reznica s dijelom grane bila je signifikantno veća i od prosječne duljine korijena jednostavnih, i reznica s petom, neovisno o kultivaru. Kako bi se postiglo bolje ukorjenjivanje, u rasadničarskoj proizvodnji oba kultivara preporučuje se upotreba reznica s dijelom grane.; Influence of cultivar and type of cuttings on rooting percentage and root length in northern white cedar (Thuja occidentalis) was investigated. Two cultivars ('Columna' and 'Smaragd') with three types of cuttings (simple, heel and mallet cuttings) were included in the trial. Rooting percentage was significantly influenced by the cultivar and type of cuttings while the root length was significantly influenced by the type of cuttings. Higher average percentage of rooted cuttings was recorded in cultivar 'Smaragd' compared to 'Columna' cultivar. Average percentage of rooted cuttings was higher in both cultivars with the use of mallet and simple cuttings, compared to heel cuttings. Average root length of mallet cuttings was significantly longer than average root length of both simple and heel cuttings, independently of cultivar. In order to achieve better rooting, in the nursery production of both cultivars, use of mallet cuttings is recommended.