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. The differences of their growth rate were significant and therefore those differences have a certain practical value. 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 than those obtained after self-pollination (in consanguine population). This phenomenon could be a consequence of partial splitting of heterozygote and accumulation of homozygote in posterity after elf-pollination, factor that influence the growth of obtained genotypes. In consanguine population was observed the high level of genotypes variation, accompanied with a low level of some part of saplings viability and vigor. Slow growing of oak saplings determines the difficulties of their maintenance, especially during the first 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 r obtain viable and vigor descendents of pedunculate oak.