Veronica austriaca Knallblau

Veronica austriaca Knallblau is a variety of Austrian veronica that is particularly attractive due to its medium blue, extraordinarily vibrant flowers. Short but numerous spikes emerge in spring from a compact green-grey leafy carpet of vegetation that disappears in winter. This undemanding flowering perennial will be happy in ordinary, well-drained, even rocky and limestone soil. It likes sunny borders but does not mind semi-shaded rockeries or light woodlands. It will find a place in a cottage garden or a small informal bed.

Veronica austriaca, also known as Veronica teucrium or Germander speedwell, is a small woody perennial plant of the scrophulariaceae family. It is native to temperate areas of central and southern Europe, but also widespread in western Asia. The 'Knallblau' selection is distinguished by the particularly vibrant blue of its small flower spikes. It develops numerous initially prostrate branches which quickly straighten up to reach about 30 cm (12in) in all directions. Its stems bear small deciduous, ovate, pretty bright green leaves, with toothed edges, similar to Teucrium chamaedrys (germander shrub). From May to August, earlier or later depending on the climate, it produces small, blue flowers 1 to 2 cm (0 to 1in) in diameter in compact clusters  10 to 12 cm (4 to 5in) long at the end of the stems. The flowers start to bloom at the base of the spikes, then gradually open up to the top.

Veronica austriaca Knallblau is a lovely dwarf variety for good, well-drained, even rocky and limestone soil, in semi-shade. The soil must be moist if planted in full sun. It will be very useful and beautiful in a semi-shaded rockery with small chamomiles (Chamaemelum nobile, Anthemis tinctoria, Anthemis cretica) or as a border plant with Rhodanthemum hosmariense (in not too cold climates), Antennaria dioica Rubra, Pulsatilla or even blood-red perennial geranium. Under the cover of sparsely dense bushes, it can be planted alongside dead nettles, Waldsteinia ternata or Epimedium.