The growth rate of Quercus robur L. saplings obtained from the germinated acorns sowed in the autumn and spring was investigated. The growth rate of descendents obtained from the spring sowed acorns was revealed to be much higher than those obtained from the autumn sowing. It was also demonstrated the importance of collecting the acorns formed in conditions that assure cross-pollination of trees (from polymorphic population). Saplings obtained from this population grew much faster in comparison with those obtained after self-pollination (in consanguine population). In consanguine population the high level of genotypes variation was observed, accompanied with a low level viability and vigor of some part of saplings. Slow growing of oak saplings determines the difficulties of their maintenance, especially during the first two years of life. Thus, cross-pollination and spring sowing of the obtained acorns are the two factors that are important to take into account when we want to obtain viable and vigor descendents of pedunculate oak.