Garden with Insight v1.0 Help: heat units

For any given plant, the number of days from planting to harvest tends to be well correlated with the temperature the plant experiences over that time. For this reason, temperature is often used to predict plant development. Heat units are accumulated degrees of temperature (Celsius) between the day's mean temperature and the plant's minimum growth temperature. The number of days in which the air temperature was high enough for the plant to grow is a good predictor of a plant's physiological age. Your heating bill may have a graph of heat units, which are also called heating or cooling days (or degree days), as an index of how hot or cold the season has been in relation to other years.

How it works:
heat unit accumulation