Ionopsidium acaule Starry Blue Blaze

The Starry Blue Blaze stemless Ionopsidium acaule is one of those little-known annual plants among French gardeners. Yet its ancestor comes from the sandy and humid dunes of Portugal. There, this small annual plant takes advantage of the humidity and mild winter to flower in a blue mist with a hint of honey fragrance in the most deprived lands one can imagine. In our gardens, we can enjoy its flowering throughout the summer by sowing it early in the spring, directly in place or in small pots to perfume the terrace or balcony. Give it a semi-shaded to shaded exposure and a fresh, light soil.

Ionopsidium acaule (synonym Cochlearia acaulis) is an annual herbaceous plant native to the irrigated areas of southern Europe. It is endemic to the coasts of southwestern Portugal, and widespread in northwestern Italy and southwestern France. It can be found on humid and sandy soils, in sand dunes, clearings, or sometimes along roadsides. This species can tolerate moderate trampling. Uts flowers seem to shine like small stars in partial shade. Jonopsidium acaule belongs to the Brassicaceae family, formerly called crucifers, just like rapeseed and mustard. The cultivar 'Starry Blue Blaze' was selected for the bright mauve-blue colour of its flowers and its very rapid growth, allowing it to flower 6 to 8 weeks after sowing regardless of the season, if the climate permits.

It is a low plant, forming mossy carpets 10-15 cm (4-6in) tall when in bloom and spreading up to 20 cm (8in). It consists of stems bearing basal rosettes and stem leaves. The basal leaves are rounded oval and 1.2 cm (1in) wide, while the stem leaves are mostly divided into 3 to 5 lobes. they are all shiny and dark greenish olive. A plant sown in late summer will persist in winter in favourable climates (zones 8-9) and will flower before the arrival of heat and drought. Spring sowing takes about 7 weeks to flower. From July to September, depending on the sowing date, tiny solitary flowers appear in the axils of the leaves, carried by long peduncles. Each flower is composed of 4 mauve-blue petals. They are insignificant when observed individually but produced in such abundance that each plant seems adorned with a dusting of blue stars. This flowering exhales a very pleasant honey fragrance. It gives way to numerous seeds that will easily germinate in light and sandy soil.

With its lovely cloud-like habit and airy flowering, the Starry Blue Haze Ionopsidium acaule is superb in borders, emphasising the design of a pathway or the curve of a bed. You can also plant it in small patches, between the stones of an alpine rockery where it is not too dry and rather shady, with saxifrages and heucheras for example. This little plant can also grow as a lovely bluish lawn, in a shaded and less frequented area of the garden. Starry Blue Haze Jonopsidium will adorn troughs and planters, at the foot of perennials or shade-loving shrubs. To fully enjoy its flowering, place it near high-traffic areas or not far from the terrace.