Plant Profile: Astrantia (Masterwort)

Astrantia is one of several umbellifers (see also Eryngium) with ornamental bracts, a feature that offers significant added value in urban contexts: tougher and more membranous than flower petals, bracts are more durable and give a longer display in demanding city conditions.

Astrantia “flowers” are actually inflorescences consisting of a rosette of coloured bracts (involucre) above which sits a compound head of many tiny individual florets, the whole inflorescence resembling a fuzzy pincushion.

The cultivars—complex hybrids of A. major and A. maxima — range from deep burgundy purple through red to pale pink and white, often attractively tinted with green. Some varieties also have coloured stems (‘Claret’ and ‘Hadspen Blood’).

The flowers are held on sturdy stems above clumps of lobed, glossy basal foliage, which remains attractive throughout the season. Flowering begins in spring (May) and continues throughout the summer.

Native to woodland edges and meadows in Europe and the Caucasus, Astrantia is happiest in dappled shade on retentive soil (including clay), but it also thrives in open positions, provided the soil is not bone dry — this makes it an excellent candidate for mixed plantings in urban swales. Given sufficient moisture, Astrantia is a remarkably tolerant genus, able to perform in a variety of conditions on either side of its ideal environment.

Plants are long-lived in situ: clumps gently expand by stolons, and some cultivars self-seed (and cross-fertilise), so if predictability is desired, it may be worth specifying sterile forms — these generally last longer in flower, as well as repeat-flowering without being cut back.

Among sterile varieties, the pink-white ‘Buckland’ offers extended flowering, while Piet Oudolf’s vigorous mid-pink selection ‘Roma’ is deservedly one of his signature plants.

Netherlands-based breeder Future Plants continues to release new varieties, including the sterile selections ‘Pisa’ (white flowers, floriferous, 60cm) and ‘Capri’ (striking deep pink, 70cm).

This article was first published in the February 2024 issue of FloraCulture International. The author is Martin Deasy, a UK-based horticulturist and landscape designer.