Sour cherry (Prunus cerasus L.) is one of the most important fruit crops in Poland. There are many varieties cultivated in orchards, but only a few of them play an important role in commercial production. These few varieties have been the object of numerous studies focused on practical aspects like growth performance, yielding, or resistance to diseases. Recently more belowground research has been carried out in pomological plants using the minirhizotron research allowing to observe roots in short and long term experiments. There have been very few studies concerning root growth dynamics of sour cherry cultivars. Here we studied the influence of four major factors on root growth: the cultivar, root diameter, soil depth, and season on the survivorship of fine roots. We used the minirhizotron technique (MR) to examine fine roots dynamics of four sour cherry cultivars grafted on the Mahaleb rootstock, grown in an experimental orchard in Central Poland. The results revealed that the greatest impact on root survivorship was exerted by root diameter, depth of root formation and the season, whereas cultivars had no obvious influence. The finest roots (with a diameter <0.2 mm) and roots formed at a depth of down to 10 cm below the soil surface had the shortest survivorship. On the other hand, thicker roots (>0.75mm) and roots formed at a depth of more than 50 cm below the soil surface have the longest survivorship. The season of root growth has little impact on root survivorship, but has a big influence on the number of the roots formed. There is no impact of the cultivar on the differences in observed roots survivorship.