Spiraea nipponica is a species of flowering plant in the family Rosaceae, native to the island of Shikoku, Japan. Growing to 1.2–2.5 m tall and broad, it is a deciduous shrub with clusters of small, bowl-shaped white flowers in midsummer. Spiraea nipponica, commonly called spirea, is a dense, upright, mounded, deciduous shrub that typically matures to 5-8’ tall with a slightly larger spread. It is native to the island of Shikoku, Japan. Obovate to elliptic leaves (to 1 1/4” long) are dark green above but blue-green beneath with round toothed apices. Foliage turns a minimally attractive yellow in fall. Tiny white five-petalled flowers in rounded hemispherical clusters (corymbs) cover the foliage in late spring to early summer (late May to June). Flowers are attractive to butterflies. Genus name comes from the Greek word speira meaning wreath in reference to the showy flower clusters seen on most shrubs in the genus. Specific epithet refers to this shrub as being a native of Japan.
Keep newly planted spireas well-watered until they become established. mature spireas are drought tolerant and only need watering when the soil becomes dry. spireas don't like wet feet, so avoid oversaturating the soil.
Use a fertilizer formulated specifically for your plant. Avoid over-fertilizing and follow the instruction on the label.
The ideal blend of soil for plant growth is called loam. Often referred to as topsoil or black dirt by landscape companies, loam is a mixture of sand, clay, and silt.
Increase pot size by 2.5-5 cm (1 to 2 inches) in diameter for plants that are growing in pots 25.4 cm (10 inches) in diameter or less. For larger plants, those growing in pots greater than 10 inches in diameter, increase the pot size by 5 or 7.62 cm (2 or 3 inches) in diameter.