Hypericum japonicum, commonly known as matted St. John’s-wort, is an annual herbaceous plant native to a variety of habitats including moist areas, grasslands, and open woodlands across the Indian subcontinent, China, Southeast Asia, Australasia and Oceania. It is a low-growing plant, typically reaching only 10-30 cm in height, with a spreading habit that forms dense mats. The small, yellow flowers bloom in summer and are less showy compared to other St. John’s-wort species, but they can still add a subtle charm to garden settings. The plant also features delicate, oblong leaves that contribute to its fine-textured appearance.

Matted St. John’s-wort is valued for its ground-covering ability, which can help prevent soil erosion and suppress weed growth. It is often used in rock gardens, borders, and as a filler in mixed beds due to its low stature and spreading nature. This species prefers moist, well-drained soils and can tolerate a range of light conditions from full sun to partial shade. While it is generally low-maintenance, it can become invasive outside its native range, so gardeners should be cautious and check local regulations before planting.CC BY-SA 4.0