The paper presents the results of the impact of ectomycorrhiza and humic acids on major morphological features of 1 year old seedlings of Paulownia tomentosa × Paulownia fortunei (9501) hybrids grown from root cuttings. Paulownia has many desirable properties as well as negative traits such as invasiveness. Experimental plantations were established in the spring of 2015 on a field in Zagreb. We used two different spacings (2x2 m and 4x4 m), each with two treatments and control. In the first treatment we planted seedlings grown from root cuttings inoculated with ectomycorrhizal fungi at the time of planting. For the second treatment we used the inoculated plants with the addition of soil humic acids. Seedlings were planted in flower beds with black plastic foil and a trickle irrigation system. Major morphological features of seedlings were measured at the end of the first growing season. A positive impact of the ectomycorrhizal fungi and humic acids on morphological characteristics of 1 year old seedlings was established. For the planting distance 2x2 m we established significant differences between the seedlings treated with ectomycorrhizal fungi and seedlings treated with ectomycorrhizal fungi and humic acids compared to the control seedlings in the following variables: total seedling height, stem diameter at 10 cm from ground level, number of branches, seedling height to the first live branches and length of the longest branches. For the planting distance 4x4 m we obtained statistically significant differences between the seedlings treated with ectomycorrhizal fungi compared to the control seedlings in the following variables: stem diameter at 10 cm from ground level, the number of branches and the length of the longest branches. The application of ectomycorrhizal fungi and humic acids can increase the quality of forest plantation of paulownia. Before growing and putting paulownia seedlings on the market we should consider the fact that in Croatia there are no scientific or impact studies on the nature of several species from the genus Paulownia , and the risks should be assessed for each taxonomy category, even lower than the species. Such studies would give specific guidelines and plans for future plantations of paulownia. U radu se prikazuju rezultati utjecaja ektomikorize i huminskih kiselina na važnije morfološke značajke jednogodišnjih sadnica hibrida Paulownia tomentosa x Paulownia fortunei (9501) uzgojenih iz korijenskih reznica. Paulovnija ima brojna poželjna svojstva, ali i negative osobine poput invazivnosti. Pokusna plantaža je osnovana u proljeće 2015. godine na poljoprivrednom zemljištu na području grada Zagreba. Korištena su dva razmaka sadnje (2x2 m i 4x4 m), svaki s dva tretiranja i kontrolom. U prvom tretiranju sađene su sadnice uzgojene iz korijenskih reznica koje su inokulirane s ektomikoriznim gljivama u trenutku pikiranja. Drugo tretiranje bilo je s inokuliranim sadnicama uz dodatak tlu huminskih kiselina. Sadnice su posađene na gredice s crnom pvc folijom, ispod koje je postavljen sustav natapanja kap na kap. Važnije morfološke značajke sadnica su mjerene na kraju prvog vegetacijskog razdoblja. Utvrđen je pozitivan utjecaj primjene ektomikoriznih gljiva i huminskih kiselina na morfološke značajke jednogodišnjih sadnica. Kod razmaka sadnje 2x2 m su utvrđene statistički značajne razlike između sadnica tretiranih ektomikoriznim gljivama i sadnica tretiranih s ektomikoriznim gljivama i huminskim kiselinama u odnosu na kontrolne sadnice u sljedećim varijablama: ukupna visina sadnica, promjer stabljike na 10 cm od razine tla, broj grana, visina sadnica do prve žive grane i duljina najduže grane. Kod razmaka sadnje 4x4 m utvrđena je statistički značajna razlika između sadnica tretiranih ektomikoriznim gljivama u odnosu na kontrolne sadnice u sljedećim varijablama: promjer stabljike na 10 cm od razine tla, broj grana i duljina najduže grane. Primjena ektomikoriznih gljiva i huminskih kiselina može povećati kakvoću šumskih plantaža paulovnija. Kod puštanja u promet sadnica paulovnija i uzgoja istih treba se uzeti u obzir činjenica kako u Republici Hrvatskoj ne postoje znanstvena istraživanja i studije utjecaja vrsta paulovnija na prirodu, pri čemu rizik treba procjenjivati za svaku taksonomsku kategoriju, pa i nižu od vrste. Takve studije bi trebale dati konkretne smjernice i planove za buduća podizanja plantaža paulovnija.