Tree buds blossom at a different time each year. We know that factors such as day length and temperature have a certain influence on this, but scientists don't know the exact mechanism behind this. Global warming also interferes with this mechanism; winter and spring temperatures rise, which cause trees to blossom earlier. This also means that there is a greater chance of frost damage.

Scientists want to know more about this mechanism, but there are too many trees for too few scientists. Citizen scientists can contribute to science by studying the process and gathering a lot of data. They can help the project along by repeating the same experiment each morning and each night, and sending the data to the researchers. The project aims to reach schools (third and fourth year of secondary school) and have pupils collect the data.