Spiraea hypericifolia aka Iberian Spirea

Spiraea hypericifolia, or Iberian spirea, belongs to the rose family. This deciduous shrub comes from southeastern Europe and much of Asia. Its range includes central and southwestern Asia, China, Mongolia and Siberia. It grows in open woods, thickets and dry, sunny slopes. It is not native to Britain or Ireland. Garden escapes have become established in parts of Mississippi.

This compact shrub grows about 3–5 feet (0.91–1.52 metres) tall. It can spread to about 5 feet (1.52 metres). Its branches grow upward and outward, giving it an upright shape. The small leaves reach about 0.07 feet (0.02 metres) long. Their shape ranges from oblong to narrow with wider tips. Each leaf narrows toward its base. The tip may be blunt or pointed. The shrub sheds its leaves for winter.

White flowers form tight clusters in May and June. Each cluster holds five to ten small, star-shaped blooms. The flowers can cover much of the foliage in late spring. Butterflies visit the blooms, making this shrub useful in butterfly gardens. Flowers grow on wood formed in past seasons. Prune just after flowering when the shrub needs shaping. Removing spent flower clusters may help it bloom again. Light shearing offers another way to remove these faded blooms.

Grow Iberian spirea in full sun with well-drained soil. It accepts a broad range of soils and needs moderate moisture. It also tolerates drought, though that does not replace its moisture preference. Chicago Botanic Garden lists it for USDA zones 5–8. The Missouri Botanical Garden describes it as easy to grow. Its care needs are low. Plant it in groups within shrub borders or near foundations. It can form a low hedge beside paths and walks. Its size also suits beds, borders and screening uses. Reported resistance includes deer, rabbits, drought and erosion.

Serious pest and disease trouble is not usual for this species. Even so, several rose-family problems can affect it. These include leaf spot, fire blight and powdery mildew. Root rot is another possible problem. Aphids, leaf rollers and scale insects may also attack it. These risks qualify its low-care status rather than rule it out.