Investigations of spruce growth were carried out in middle Karelia (northern boreal subzone) in spruce forests of Vaccinium myrtillus – type and Sphagnum – type of 78-85 years old. It was found that shoots begin to grow first in the end of May. Then 1-2 weeks later young needles appear and in a decade division of trunk cambium cells begins. Trunk accretion culminates at the end of June and beginning of July. Accretions of shoots and needles reach maximum in the second and third decades of July. Growth of shoots ceases at the end of July. Cessation of needle and trunk growth takes place in the second and third decades of August, correspondingly. The longest duration of growth (57-79 days) is characteristic of needles. Growth of shoots and trunks lasts for 52-66 days. It was established that beginning of shoot growth does not depend on forest type, while growth of needles and trunk wood begins 5-10 days earlier and ceases 5-10 days later under favorable conditions. All these reasons lead to 2-3 week longer period of vegetative growth in spruce forests of Vaccinium myrtillus – type compared to spruce forests of Sphagnum-type. Besides, the intensity of vegetative growth increases under favorable soil conditions. All these results in increased annual accretion of shoots, needles and trunks by 15-30%.