Carduus nutans aka Musk Thistle

Carduus nutans is known as musk thistle or nodding thistle. It belongs to the daisy family, Asteraceae. This biennial grows across its native range in Eurasia. It is native to Britain and Ireland. It grows in pastures, fields, and ground left unused. Dry grassland, road verges, and dunes also suit it. Many sites have lime-rich soil.

Plants reach about 1.6–3.3 feet [0.5–1 metre] tall and wide. The form is upright and bushy, with downy stalks. Green leaves have deep divisions and sharp spines. Some foliage stays green through winter. Spines also arm the bracts around each flower head. The purple heads hang down, giving nodding thistle its name. They open from June to August. Each head measures about 1.2–2 inches across. Pink bracts form a ring around the head. The flowers lack ray florets.

Grow this thistle in full sun with good soil drainage. Chalk, loam, and sand suit it. It prefers soil with a neutral or alkaline pH. Its moisture range runs from dry to moist. The RHS lists sheltered sites facing south or west. It gives the plant an H7 hardiness rating. Plants For A Future lists USDA zones 3–9. Seed provides the means of propagation, and pruning is not needed. The RHS reports few pest or disease problems.

The RHS suggests it for wildlife gardens and wildflower meadows. Bees, hoverflies, and butterflies visit the flowers. Insects carry out most pollination. Its leaves also feed the caterpillars of many moths and butterflies. Birds and small mammals may eat the seeds. Yet these wildlife uses come with a clear drawback. Plants For A Future describes it as an invasive weed. Its aggressive spread makes it a problem for land managers. Its down has served as a source of paper fibre. The seeds also contain oil.

Leaves, upper stems, and flower receptacles have food uses. Preparing them takes much work and gives little food. All spines and tough fibres need removal before eating. The inner stem pith can be boiled. Prepared parts have a mild, bitter taste like artichoke. Dried flowers can help curdle plant milks. Spines can injure skin, while remaining fibres may irritate the throat. No toxic compounds are documented in the edible parts. This does not establish the safety of the whole plant. Roots lack food-safety records and should not be eaten. Avoid plants from sites treated with herbicides.