Narthecium ossifragum aka Bog Asphodel

Narthecium ossifragum, or bog asphodel, is a deciduous perennial wildflower. It belongs to the family Nartheciaceae. Its native range runs from southeastern Sweden to northern Portugal. It is native to Britain and Ireland as well. Suitable sites in northern and western Britain support this plant. It also grows in suitable habitats across Ireland. Other names include Lancashire asphodel, maidenhair, and yellow grass. The Welsh name is llafn y bladur.

The plant forms a tuft and spreads through rhizomes. These underground stems allow it to spread beyond the first tuft. Its leaves sit in a flat cluster, like a small iris. The foliage drops away rather than staying green all year. In autumn, the whole plant takes on a dark orange shade. This change adds a second season of colour after summer flowers. The RHS gives a maturity period of two to five years. The supplied sources give no mature height or spread.

Spikes of rich yellow flowers rise above the leaf tufts. Each flower has a star-like shape. Bloom comes in summer, though the sources give no exact months. The flowers offer pollen for bees. Red seed capsules follow the flowers, adding colour after bloom. Flowers, capsules, and autumn foliage give the plant changing seasonal interest. Its value in a garden includes this colour and bee pollen.

Bog asphodel grows in acid bogs, moorland, and wet peat. Garden conditions need to reflect these wet, low-nutrient sites. Give it full sun and soil that stays wet throughout. The soil should be acidic, rich in humus, and poor in nutrients. The RHS lists loam and poorly drained conditions as suitable. It accepts either an exposed or a sheltered position. South-facing and west-facing sites match the listed growing conditions. Its RHS hardiness rating is H5. This covers most UK sites, even during severe winters.

Its habitat needs make it a plant for wet, acidic sites. It is not suited to a bed that dries out. The RHS reports few usual pest or disease problems. No pruning is needed. Plants can be raised from seed or divided. The supplied evidence gives no food uses or safety assessment. It therefore provides no basis for treating any part as edible.