AbstractCambium samples ofThuja occidentalisL. were collected at five different times, covering spring reactivation and early and late resting period, and used for sucrose determinations. Fragments of the different cell types ‐ xylem ray, cambial initials, sieve‐elements including phloem parenchyma cells, phloem ray ‐ were dissected from freeze‐dried radial sections and analyzed individually. Results show large differences in sucrose concentrations in the different cell types of the cambial layer. In addition, each cell type also shows seasonal fluctuations in sucrose content, whose amplitudes and patterns of variation appear specific for the particular ce