Data for the manuscript "Is it cold enough? Effects of artificial and natural chilling on "budbreak and frost hardiness in Acer saccharum (Marsh.)" under review on the journal Physiologia Plantarum.

A brief explanation of the data is provided here. Further information on the data are noted in the excel files (“metadata” sheets). For more information on the methodology please refer to the main manuscript. · The files DBB_2023 and DBB_2024 show the budbreak observations (by DOI) after transferring the plants from chilling to forcing conditions. 2023 refers to experiment 1 (winter 2023/2024) and 2024 to experiment 2 (winter 2023/2024). Please see the main manuscript for further details, including the phenological scale used in the study. · REL shows the Relative Electrolyte Leakage test results, including conductivity measurements. · Chilling_accumulation shows the calculated accumulation of chilling units for different dates of transfer to forcing conditions, using several different models for chilling computation.