Iris germanica Delta Blues

Iris germanica 'Delta Blues' is a tall and elegant bearded iris. Its large and beautiful flowers, with their undulating petals, display a magnificent lavender blue colour, delicately veined in a deeper shade of blue and highlighted by white beards. This iris can bear up to 10 flower buds per stem, ensuring long mid-season flowering. It is stunning in the garden in spring and its flowers are superb in bouquets.

The 'Delta Blues' iris is a perennial rhizomatous plant that develops in spring into elegantly upright clumps, with its foliage disappearing in winter. It belongs to the Iridaceae family. It is one of many cultivars obtained over the centuries, with debate about their disputed origins revolving around the number of chromosomes of potential ancestors. It should be noted that Bearded Irises have European origins. They are plants that thrive in calcareous soils and require plenty of sunlight, with their rhizomes needing to "cook" in summer in order to bloom. A minimum of 6 hours of sunlight per day is generally required.

'Delta Blues' can reach a height of 90 cm (35in) when in bloom, under good growing conditions. The clump can spread indefinitely over time, with the central rhizomes thinning out in favour of the outer ones. The foliage consists of long and wide sword-shaped leaves, of a slightly glaucous green colour and with parallel veins. In April floral stems appear, giving rise to 8 to 10 large flowers in May-June, which open from the top down towards the lower branches. The very bright colour of this plant is, as always with Bearded Irises, enhanced by the thick and iridescent texture of the upright petals and the trailing sepals. Note that the flower is not fragrant.

Obtained by Schreiner, 1994

Awards: HM (Honorable Mention) in 1996 and AM (Award of Merit) in 1998.

To complement irises, choose plants based on their needs (sunlight, soil), their "respectful" growth habit vis-a-vis irises (low-growing plants or light foliage), and how they complement each other visually (appearance, flowering period). For example, Gauras will cast little shade and will keep the bed attractive throughout summer once the irises have flowered. California Poppies (Eschscholzia), like irises, will be satisfied with dry and poor soil. Perennial geraniums, salvias, and Libertia also complement irises very well. Slopes and terraced edges can be stabilised by dense planting of old diploid varieties that can remain in place and require little care. If the goal is more decorative and access for care is possible one can choose more modern varieties, such as intermediates that are less likely than tall varieties to be knocked over by wind and rain.

Tip: avoid large masses of just irises, instead placing a few carefully chosen clumps among other plants with staggered flowering times.