The carbon allocation to current‐year shoots of the deciduousVaccinium uliginosumL. and the evergreenV. vitis‐idaeaL. was studied in a field experiment using14C. During the first week after labelling, 0–50% and 30–80% of the initially assimilated14C was lost inV. vitis‐idaeaandV. uliginosumrespectively. Later on, the losses were smaller. After leaf fall inV. uliginosum, 30, 10 and 8% of the initially assimilated14C was recovered in the abscised leaves, in plants labelled 1 July, 1 August and 1 September, respectively. The amounts found in the oldV. vitis‐idaealeaves the year after labelling were 33, 20 and 10%. Only traces of past‐year assimilates were found in the current‐yearV. vitis‐idaealeaves, while it was estimated that theV. uliginosumleaves contained 10–15% of the past‐year label. It is concluded thatV. vitis‐idaeais mainly dependent on early summer assimilates ‐ produced by leaves that have overwintered – for the current year shoot growth, while past‐years' assimilates probably make an important contribution to the leaf expansion inV. uliginosum.When fruits occurred, a large fraction of the14C assi