Picea omorika is a self-fertile but outcrossing conifer.

Outcrossing rates were estimated in a natural Yugoslavian and in a cultivated Finnish population of Serbian spruce [Picea omorika (Pančić) Purk.]. The outcrossing rates in the cultivated stand in two years were 0.98 ±0.03 and 1.02 ±0.04, and in the natural stand 0.84 ±0.05. The relative self-fertility was estimated in seven trees in the cultivated population. The results indicate high self-fertility, which agrees with the earlier information. The high self-fertility combined with high outcrossing rate shows that Serbian spruce, in contrast to most other conifers, employs other means than early acting inbreeding depression to avoid selfing.