Iris sibirica Colonel Mustard - Siberian Iris

Iris sibirica 'Colonel Mustard' is a Siberian iris with shimmering colours in caramel tones. Its flowers combine golden bronze with pale-yellow, with a touch of mauve in the centre for a beautiful effect. They bloom in June and July on a medium-sized upright plant. The so-called Siberian irises are beautiful plants for wet or cool soil, appreciated for the grace and elegance of their flowers and fine foliage. They form sculptural and vigorous clumps, as beautiful in a contemporary garden as in a romantic one, and are ideal near water features.

Iris sibirica 'Colonel Mustard' is a rhizomatous and deciduous perennial plant, with a clumping habit from spring onwards. It belongs to the Iridaceae family. It is one of the many cultivars obtained from I. sibirica, native to Central Europe, Eastern Europe, and Turkey, but absent from Siberia, and I. sanguinea, present in China, Siberia, Japan, Manchuria, and Korea. This iris reaches a height of 70cm (28in), 1m (3ft) when in bloom, and the clump spreads over 50 to 70cm (20 to 28in). Its growth is moderate, slower than that of I. germanica. 'Colonel Mustard' has an upright, elegant habit with dense clumps. The foliage consists of long, narrow, green-grey leaves. In early summer, the flower stems project above the foliage, with 3 sepals and 3 petals arranging themselves and succeeding from the tip of the stem to the lower branches. They have a coppery bronze and pale-yellow colour, marked with mauve. This iris spreads by rhizomes.

The 'Colonel Mustard' Siberian iris tolerates a wet situation, for example, on a riverbank, as long as it is not permanently submerged. It can also be grown in ordinary mulched garden soil, as long as it remains moist. It prefers acidic to neutral (pH 4.5 to 8), rich, and well-drained soil. It is irreplaceable on the edge of a water feature or stream, or simply in moist soil. Its grace is perfect for romantic gardens, English gardens, and other mixed borders. It can be planted with summer snowflake, camassia, daylilies, delphiniums, and columbines, with which it forms a perennial flower bed from April to July. In a contemporary garden, it can be planted on the edge of a water feature alongside hostas or astilbes in partial shade. The shimmering colours of 'Colonel Mustard' go wonderfully well with purple and mauve blooms.

Note: The wild Siberian iris (Iris sibirica L.) is an endangered and protected species that must be respected. Horticultural Siberian irises are the result of hybridisation between different species of the Sibericae series (I. sanguinea, etc.). Their flowers are larger than those of wild forms and come in various colours. Several hundred named cultivars have been registered.