The most serious problem of intergeneric and interspecific hybridization is related to overcoming the reproductive isolation of different species. We assessed the efficiency of reproduction under in vitro conditions and the ex vitro growth capacity of interspecific hybrids of Vaccinium uliginosum × (V. corymbosum × V. angustifolium). The percentage of seed germination in in vitro culture was 88% for V. uliginosum, form No. 8 × (V. corymbosum × V. angustifolium), SC5-8, while it was 42% for V. uliginosum, form No. 8 × (V. corymbosum × V. angustifolium), ‘Northcountry’. The analysis of mean value showed that the multiplication rate increased and the shoot height decreased as the 2-isopentenyl adenine (2iP) concentration was increased in the nutrient medium of the studied hybrids. The maximum rate was achieved using 15 μM 2iP. A detailed analysis of the hybrids indicated that the hybrid variant reliably affected growth and development indicators. Inter simple sequence repeat analysis demonstrated that all analyzed hybrids inherited DNA fragments of the parent plants in various combinations, confirming their hybrid nature. Thus, the use of in vitro methods for the propagation and further selection of genotypes is demonstrated as being an effective approach for developing interspecific hybrids of V. uliginosum × (V. corymbosum × V. angustifolium).