Salvia smoulders deeply
There are lots of kinds of Salvia, including the red-flowered bedding plants, but there is a particular group of related species and hybrids that offer a dark-coloured contrast to the bright and soft colours of a summer border.
The introduction of some deep, dark colour sets off the other lighter colours and brings a border to life. These plants typically hold their flowers in rigid upright spikes, adding contrast of shape and texture as well as contrast of colour.
The best-known is Salvia 'Superba', a bushy perennial with many stems branching to make upright spikes. These carry dozens of tiny flowers, small, tubular and slightly hooded, and enclosed by dark bracts which are long-lasting, conveying their brooding presence long after the true flowers have faded.
Another of these dark flowered Salvias is 'Ost Friesland' with many spikes of deep blue. This is a smaller grower than 'Superba', which can reach about 90cm, and suits smaller beds and borders better. The flowers are deep blue and the bracts just behind the flowers are purple-blue.
'Lubecca' is also smaller, to about 45cm, with grey-green leaves, and produces violet-blue flowers with persistent purple bracts, effective from mid-summer to early autumn. 'Blaukonigin', also sold as 'Blue Queen', is taller, about 70cm, and 'Blue Mound', or 'Blauhugel', is a bit smaller.
Also very well-known and widely grown is 'Mainacht', or 'May Night', to about 60cm, with bolt-upright stems of dark indigo-blue flowers and these are produced relatively early. 'Caradonna' is an outstanding, relatively new addition with deep violet-purple spikes appearing from early summer (shown with yellow achillea). 'New Dimension Pink' is a soft-pink purple but still has the spikes and a brooding look. Bees and other flying insects love these flowers as a nectar source. To see how the smouldering look might work, buy a single Salvia plant in flower and try it, still in its pot, toward the front or middle of a border. Work out the best place to locate it, and ideally several places, and plant a few. Apart from enriching a border, these plants play off each other very well, planted in a few spots in a border, or in facing borders.
In fact, these Salvia plants just on their own are rather dull, but they are so distinctive that they make superb contrast in combination with other flowers of different shape.
Salvias are easy to grow, hardy and thriving in any soil - taller and more robust in good soil, shorter in poor soil. But the soil must not be too heavy or moisture-retentive, and definitely not water-logged for long periods in winter because the roots rot if the drainage is not good. And they are plants of sunshine.