What is a Japanese Spirea?

Japanese spirea is a flowering shrub distinguished by its pastel pink, “hairy” flowers. Also called by its scientific name, Spiraea japonica, and by the nicknames maybush or Japanese meadowsweet, the plant is native to Japan, the Koreas, and China, but was introduced to North America in the 19th century. Japanese spirea has a pleasant appearance, making it a popular ornamental shrub. Due to its extreme invasiveness, however, some plant experts caution against introducing it to one’s garden.

Perhaps the most distinct feature of the Japanese spirea is its pink blossom clusters, each of which is made up of approximately 18 to 30 flowers. These flowers consist of five very small, rounded petals. Numerous very fine stamens project from the center of each flower. These stamens give the plant’s flower clusters an unusual appearance of hairiness when they are viewed from a distance of several feet.

The Japanese spirea grows in a shrub form which typically reaches around 3 to 6 feet (0.91 to 1.83 meters) in height. Its width is usually roughly equal to its height. The plant’s stems are usually brown or reddish brown in color. Its leaves are dark green in hue, creating an attractive contrast with its pink flower clusters. These leaves are shaped like thin ovals with pointed tips, and usually measure .33 to 1 inch (0.76 to 2.54 cm) in length.

While it is native to the Asian countries of Japan, the Koreas, and China, the Japanese spirea was introduced to North America in the 19th century, and has become a familiar presence in the northeastern United States as well as some parts of Canada. The plant is most successful in locations that receive a large amount of sunlight and significant moisture. It cannot tolerate excessive heat, however, and thus in the US does not survive well in areas like Florida.

Due to its attractive appearance, many people choose the Japanese spirea to lend a decorative element to their gardens. The plant is notoriously invasive, however, and is known to crowd out other flowers and shrubs. In addition, its seeds can remain beneath the ground for several years before they begin to germinate, making the plant difficult to dig up. Thus, plant experts suggest that home gardeners carefully consider the decision to plant Japanese spirea, for once it has been planted it can wreak havoc on neighboring plants and can be very difficult to eliminate.