Two weeks ago, we started photographing the cherry trees whose spectacular white blooms mark the start of spring in the nation’s capital. We thought we had plenty of time to capture the buds gradually unfold. If history was any guide, the treesHistory, it seems, provides less guidance than it used to. Day after day of unseasonable heat drove the cherry trees to reach peak bloom on March 17.
Plants’ sensitivity to temperature explains why flowers in the countryside bloom later than in nearby cities, where concrete and asphalt trap more heat than natural landscapes. But even in rural areas, as when it came out of historical ice ages. The pace of change can cause the seasonal cycles of plants and the creatures that depend on them, such as caterpillars and bees, to get out of sync.
The Tidal Basin’s cherry trees are bred to be sterile, so they don’t grow fruit. But seasonal mismatches between flowers and pollinators could pose problems for commercial fruit growers, particularly those that use native bees rather than bred honeybees to pollinate their crops.