Soil preference: Loam, sand. Neutral. Moist but well-drained.
Flowering/fruiting month: June - July
Up to 60cm height
Up to 40cm spread
Description: 'Obsidian' is a compact, mound-forming perennial, spreading to 40cm, with distinctive lobed, glossy leaves, reddish-black in spring, darkening to near-black as they mature. Racemes of small creamy flowers are borne above the leaves in summer on dark reddish stems, usually 25-40cm, sometimes taller.
Care: Grow in fertile, moist, but well-drained soil in sun or partial shade. If the soil is moist, a shadier position may be tolerated. To prevent the rhizomes rising to the surface, mulch annually and divide every few years. Can be propagated by division; this genus need to be divided regularly. Lift the plant once in spring growth, taking small vigorous sections from around the edge. Each section should have good roots and 2-3 shoots. Remove any dead leaves and deadhead.