Blue salvias: the five best varieties

Salvia pratensis, or meadow sage

Meadow sage, or Salvia pratensis in Latin is a sage with a wild-looking appearance, very popular for its integration in naturalistic and countryside gardens. It is extremely floriferous and seduces with the intense blue-violet colour of its bilabiate spikes. The herbaceous perennial grows to about 75 cm tall, and proves to be one of the hardiest (to -30°C) that can be grown in any garden. Meadow sage flowers all summer, from May, with, as is often the case with salvias, a late-summer reflowering. Provide it with sun, well-drained soil (it dislikes stagnant moisture), ideally calcareous and poor, and you are assured of success as it is undemanding. It has the advantage of being frugal, needing little water and resisting drought well once established.
Pair Salvia pratensis with flowers with equally cottage-garden look such as scabious and white daisies (Leucanthemum).

NB: Several cultivars have arisen from the original European wild-type, among them, ‘Vanity Fair’ with a blue-washed to pale mauve magnificent shade, ‘Indigo’ and ‘Madeline’, in a white-and-blue bi-colour.

Salvia microphylla 'Blue Note'

Among shrub Salvias, there are very few varieties with blue flowers, but there is one that cannot fail to command attention: the Salvia microphylla ‘Blue Note’ is one of the newer hybrids of these arborescent salvias, and its royal blue colour is completely unprecedented. This deep blue is velvety, utterly irresistible, carried by very light inflorescences. The tiny leaves are highly aromatic, and also contribute to the plant’s light appearance. This sage remains compact, with upright stems that are well ramified, reaching a mature height of between 60 and 80 cm, so you will find it suitable for many uses: in pots, in borders and even in rock gardens.
As with most small-leaved shrub Salvias (Salvia microphylla), ‘Blue Note’ flowers from May, taking a brief pause in summer, to restart more vigorously until the frosts end its blue blooms! You will plant it in dry, even poor, very well-drained soil. It is semi-evergreen in mild climates.
Cottage garden or natural garden, it easily weaves into cool scenes, in the company of thistles or Cosmos, and a few grasses such as the Stipa tenuifolia or the Stipa pennata.

Note: The Salvia microphylla ‘Victoria Blue’ is another pretty shrub Salvia with lighter blue flowers and smaller dimensions.

Salvia nemorosa 'Crystal Blue'

The charm of Salvia nemorosa is undeniable: these sages offer hues of a characteristic blue-violet, charming in many gardens, such as the popular Salvia nemorosa ‘Caradonna’.
One of them stands out for its much softer tones: it is Salvia nemorosa ‘Crystal Blue’, a rarity prized for its unique sky-blue, bracts slightly pink, giving a lot of softness to this perennial. A restrained elegance that suits minimalist or romantic gardens. Wider than tall (45 cm by 65 cm across), this sage remains modest in size, perfect for filling small, tidy, elegant gardens as well as terraces. Plant ‘Crystal Blue’ in sun or partial shade, in soil that is always well-drained like its counterparts.
This sage lends itself to refreshing blue-and-white combinations, or with golden foliage or chartreuse greens, with for example Libertia ixioides, Blue balloon flowers, Lychnis flos-cuculi ‘White Robin’, etc.

(© Proven Winners)

Salvia 'Mystic Spires Blue'

Annual Salvias for mass planting, long available only in flashy red at garden centres, deserve a second look. They are, in fact, now available in a range of blues, notably Salvia ‘Mystic Spires Blue’. This Salvia, bred from Mexican sages, bears spike flowers in a deep blue-violet on sturdy stems forming a dense clump. Leaves are deep green, forming a fresh, lush clump. The plant grows quickly to reach about 50 cm in height with a slightly more compact spread. Flowering takes place from July to October, giving the border an extraordinary, long-lasting bluish touch. In mild climates, this annual Salvia may survive a mild winter if well protected by a thick mulch.

Pair this lovely Salvia with orange Alstroemerias, or with a few Rudbeckias, Gauras, and blue-tinted Penstemons, for a border that stays flowering for a long time in summer!

Salvia ‘Mystic Spires Blue’ (© Cultivar 413)

Salvia patens

Of Mexican origin, here is finally a hardy sage often grown as an annual here, though it proves semi-hardy (it tolerates around -8°C in well-drained soil and a sheltered position). Called gentian sage in Britain, the Salvia patens is a truly beautiful sage with enchanting colouring: a divine pale blue, slightly silvered by the velvety texture of the flowers. The flowers are fairly spaced along the slender stems, and measure about 5 cm, appearing from July to October. An exquisite look with colour that indeed echoes the intense blue of gentians. As for the foliage, it is medium green, but bright. The silhouette of this sage, about 60 cm tall, is upright, and it spreads to around 30 cm.
In terms of light, this sage enjoys full sun, but is even more beautiful in light partial shade to reveal its incredible blue. It will grow very well in rich, moist soil. Tolerant of drought, you can also grow it in pots without concerns about its performance.

Salvia patens is ideal for cottage gardens as well as container plantings. Pair it with roses or with hardy geraniums for a romantic garden, Persicarias, Agastaches, or sages in a different shade of blue such as Salvia nemorosa.

N.B.: The Salvia patens ‘Cambridge Blue’ is an annual sage with superb blue flowers, paler.