Give Now  »

Noon Edition

Why Do Plants Flower When They Flower?

Have you ever wondered why some flowers only bloom for a few days in the early spring, while others bloom much later, or all summer long?

Flowers are the reproductive organs of plants. When pollinated, flowers develop into fruits containing seeds. However, producing flowers, fruits, and seeds is not easy. Plants devote lots of resources and energy to grow these specialized organs. Thus, plants tend to synchronize their efforts with a time of year when conditions are best for reproductive success and survival.

"Annuals" are plants that grow from seed, flower, and die in one year. Since annuals need to grow leaves and stems before they flower, most annuals won't mature enough to flower until mid-summer or later.

"Winter annuals" get a jump-start on reproduction by germinating from seeds in the fall, over-wintering as rosettes of leaves and storing energy which allows them to flower early in the spring.

"Perennial" plants can live for many years and flower multiple times. Perennials have evolved many different flowering strategies. Most flower in mid- to late summer after they have had time to accumulate the resources needed to produce seeds each year.  Others, such as early forest wildflowers, grow for only a short while, blooming before the trees above them leaf out, starving them of light. These plants store energy in underground roots or stems, allowing them to flower early and quickly.

The evolution of such diverse flowering strategies is good for plants that otherwise would have to compete for the same resources at the same time. Its also is nice for us, as we get to enjoy flowers brightening the landscape throughout the growing season.

Support For Indiana Public Media Comes From

About A Moment of Science