Flower of the Week: Japanese Meadowsweet
Japanese meadowsweet (Spiraea japonica) is a common deciduous shrub. Its small, adorable flowers bloom in clusters from the tip of new branches every year. Wild Japanese meadowsweet blossoms in pink, but through years of selection and cultivation, horticulturalists have domesticized varieties with light pink, rose red, white, and purple flowers. The leaves of the plant also vary in color, including bluish-green, light yellowish-green, yellow, and brownish-red.
Japanese meadowsweet has thin leaves and lush flowers. It grows robustly, with strong branching and excellent response to pruning. Among its cultivars are dwarfed varieties as short as 60 centimeters (2 feet) tall and giant species as tall as 1.5 meters (5 feet).
A Japanese meadowsweet variety with colorful leaves
In garden landscaping, Japanese meadowsweet enjoys a reputation for being a Jack-of-all-trades, fitting perfectly in flower beds, flower borders, and lawn corners, or by the side of landscape rocks, water banks, and stone formations. It can embellish an open lawn with a single plant, or be cluster-pruned into a sphere or semi-sphere to harmonize colors with vividly-hued perennial flowers. Some varieties tolerate slight shade and grow successfully next to taller deciduous broad-leaf trees.
Japanese meadowsweet was introduced to the U.S. in the late 1800s as an ornamental plant. Due to its ability for self-propagation, superb adaptability, and tendency to expand, the USDA has been alerted about this species. Currently, the federal government does not consider it an invasive plant, but the State of Pennsylvania does. Please check with your local forestry department before planting it, and confine its expansion after planting.
No. Many people confuse Japanese meadowsweet for meadowsweet, partly because of their identical names in English. They are both in the Rosaceae family and are not so distantly related; they even look rather alike at a glance. But their similarity is limited to the appearance only.
Meadowsweet blooms
The scientific name of meadowsweet is Filipendula Ulmaria. Historically, meadowsweet has been used as a herbal medicine for headache or anti-inflammation because of its methyl salicylic acid. It was utilized by Bayer Pharmaceuticals for its famous methyl salicylic acid formulation until it was replaced by a milder salicylic acid formulation called acetylsalicylic acid, also known as aspirin.
On the contrary, Japanese meadowsweet isn’t rich in methyl salicylic acid. In fact, aspirin pills are apparently more effective as a medicine.
Japanese meadowsweet is easy to care for and friendly to beginning gardeners. One of its cultivation advantages is its high tolerance to different soil types, even heavy clay. Spring and autumn are good seasons to plant it, and the ideal planting site should have good drainage and plenty of sunshine (at least six hours of direct light daily). If the site is in the shade of deciduous trees, autumn may be a better season to plant Japanese meadowsweet, because it won’t have to compete for sunshine with taller, leafy trees.
Water newly-planted Japanese meadowsweet when the surface soil turns dry. After the plants root and grow, they develop more tolerance to wet and dry soil conditions. Japanese meadowsweet doesn’t rely much on fertilizers; one dosage of slow-release fertilizer in early spring will keep it lush for a year.
Deadhead the bushes after blooming to encourage reblooming. Prune them even during winter dormancy; Japanese meadowsweet is a fast grower and recovers quickly after pruning. Its flowers bloom once on the newly-sprouted branches each year. Pruning produces plentiful young branches, delivering more blossoms.
Size: 2-6 feet in height, 4-7 feet in spread
Hardiness: USDA Zone 3-8
Sunlight: Full sun to partial shade
Soil: Well-drained, neutral to slightly acidic
Bloom time: Late spring to summer