It’s spring. And during spring you find many plants blooming. That’s also true for the Normandie. Some plants are blooming for weeks others only for days, and some of them are blooming only under certain circumstances like the wood anemone (Anemone nemorosa). They are blooming as long as sunlight is able to reach the ground in the forests. When the trees are getting more leafs, sunlight is hindered to reach the ground and the wood anemones don’t get enough light anymore and their blooming period ends.
The forsythia on the other hand is an example for a plant blooing a few weeks.