The aim of the study was to determine the effect of mycorrhisation and mulching on the colonisation of the roots of‘Gold Milennium’ apple trees and ‘Ojebyn’ and ‘Tiben’ blackcurrant bushes by arbuscular mycorrhizal fungi. In order to assess mycorrhizal frequency, samples of roots were collected in the 2012 season from all of the experimental combinations (control, peat substrate, bark, sawdust, manure, compost, mycorrhizal substrate and straw). The results of the analyses showed that all of the different mulches had a positive effect on increasing the degree of mycorrhizal association. In apple, the highest mycorrhizal frequency (F% - mycorrhizal frequency for the entire sample) and mycorrhizal intensity (M% - relative mycorrhizal frequency for the entire sample) were observed in the roots of trees inoculated with the mycorrhizal substrate (F = 24.40%, M = 0.24%) and those mulched with compost (F = 16.67%, M = 0.17%). In blackcurrant, the highest values of mycorrhizal frequency and mycorrhizal intensity were recorded in the roots of ‘Tiben’ bushes inoculated with the mycorrhizal substrate (F = 37.78%, M = 0.38%) and those mulched with sawdust (F = 21.11%, M = 0.21%).