Predicting Spring Bloom: Science and Observation

Every spring, flowers bloom. But how do scientists know when? They look at the weather. They count warm days. This is called 'growing degree days.'

Flowers need cold winter first. Then they need warm spring days. If winter is not cold enough, flowers do not bloom well. If spring is not warm enough, flowers wait.

Different flowers bloom at different times. Cherry blossoms bloom before apple blossoms. This happens even in the same city.

Scientists also use old records. In Japan, some bloom records are very old. These records help scientists see changes over many years.

Today, spring blooms often come earlier than before. This is because the weather is changing.

Where you live also matters. Mountains, rivers, and small areas near water can change bloom time. Farmers and gardeners use this information. They plan their work around bloom time.