Spring Comes Early

Each spring, more than 1.5 million visitors head to Washington, D.C., for the National Cherry Blossom Festival to see the pink-and-white flowers on display. In recent years, however, festivalgoers have shown up earlier than ever before. It’s not because people are impatient—it’s the flowers that are ahead of schedule. The more than 3,000 trees along the National Mall’s Tidal Basin are reaching peak bloom five days earlier on average than they did decades ago.

The shifting timeline isn’t unique to the cherry trees in the nation’s capital. One study that looked at more than 120 flowering plant species in Colorado found that they are blooming earlier than ever. It’s the same in many places: Earlier blooms are happening in forests, mountains, deserts, and plains. Scientists say that these changes— along with earlier snowmelts—are key indicators of climate change, as global temperatures tick upward. “When it’s warmer, flowers bloom earlier in the spring and in the summer,” says Paul CaraDonna, a conservation scientist who worked on the Colorado study.

The National Cherry Blossom Festival takes place each spring in Washington, D.C. More than 1.5 million people go to it. The trees are covered in pink and white flowers. Visitors show up earlier and earlier each year. It’s not because they’re impatient. The 3,000 trees along the National Mall’s Tidal Basin are blooming earlier. They’re reaching peak bloom about five days earlier than they did decades ago.

Cherry trees in the nation’s capital aren’t the only plants blooming early. One study looked at more than 120 flowering plant species in Colorado. The study found that the flowers are blooming earlier than ever. It’s the same in many other places. Flowers are blooming early in forests, mountains, deserts, and plains. Scientists say that the early blooming is a sign of climate change. Higher temperatures cause snow to melt and flowers to bloom earlier. “When it’s warmer, flowers bloom earlier in the spring and in the summer,” says Paul CaraDonna. He’s a conservation scientist who worked on the Colorado study. 

A slightly earlier start to spring may sound great to people who don’t like winter, but the changes may make it tough for many species that depend on plants. If migrating birds or hungry bees can’t find their favorite food at a certain time, will they pick something else to eat? Or will they go somewhere else to find food? These are questions that scientists are trying to answer.

While some plants are shifting their patterns, not all are ahead of schedule. “Some are not changing at all, and others are actually flowering later!” says CaraDonna. Scientists are looking into these conflicting behaviors.

There are many concerns but also some short-term benefits. In Colorado, many flowering plants are in bloom more than 30 days longer than before. “This is like they have an extra month of summer vacation,” says CaraDonna. But even that may have a downside. “This may be a good thing in the short term,” he adds, “but not over the long term if things keep getting warm.”          

Spring starting earlier might sound like a good thing. But the changes may make things hard for animals that need plants at certain times of the year. Migrating birds and hungry bees might not be able to find food at the right time. Scientists want to know if these animals will change their behavior, too. They might eat new things. Or they might change where they go to find food.

And not all plants are blooming earlier. “Some are not changing at all, and others are actually flowering later!” says CaraDonna. Scientists are trying to understand why plants are behaving differently.

There are many concerns. But there are also some short-term benefits. Many flowering plants in Colorado are in bloom for longer. Some are blooming for more than 30 days longer than before. “This is like they have an extra month of summer vacation,” says CaraDonna. “This may be a good thing in the short term, but not over the long term if things keep getting warm,” he says.