The most beautiful blue-leaved perennials

Helictotrichon sempervirens 'Pendula'

Helictotrichon sempervirens ‘Pendula’ or Blue Oat Grass is one of the prettiest blue grasses. It forms a bristly and light tuft, with a beautifully open habit, reaching heights of 80 cm to 1.20 m and a spread of 40 to 60 cm. It features long, evergreen leaves of a lovely steel-blue colour. During summer, this elegant blue foliage is topped with straw-yellow spikelets arranged in trailing panicles, providing a striking presence to the plant.

Hardy down to -20 °C and drought-resistant, it is one of the most accommodating grasses that thrives in any well-drained soil. A poor soil will enhance the blue colour of its foliage.

Highly graphic and attractive all year round, it naturally fits into dry and mineral gardens, adding relief and colour to sunny borders, slopes, and rockeries. In a harmonious palette of tones, it pairs well with teasels and perennial flaxes, while the presence of a few white gaura or Gypsophila, with its delicate flowering, will highlight it beautifully.

Helectrotichon sempervirens ‘Pendula’

Euphorbia characias ‘Blue Wonder’

Another perennial that surprises with the blue colour of its leaves! Euphorbia characias ‘Blue Wonder’ forms a bushy clump 70 cm high made up of lanceolate, evergreen, grey-blue leaves. From April to June, it showcases a bright and original flowering in a chartreuse green hue, giving it a graphic and somewhat exotic appearance.

Hardy down to -15 °C, it is easy to grow in full sun in well-drained to dry soil.

It will set the tone in a silver or blue border alongside Wormwoods, Helicrysums, and Stachys byzantina, which enjoy the same growing conditions. You can create a striking tableau by pairing it with the silver foliage of Verbascum ‘Polarsommer’, and Eryngiums.

Euphorbia characias ‘Blue Wonder’

Festuca 'Intense Blue'

Another grass that stands out for the beauty of its azure foliage! The Festuca glauca ‘Intense Blue’ is probably the blue fescue with the most pronounced colour. It forms beautiful, slightly bristly, evergreen cushions, measuring 30 cm in all directions. The foliage consists of fine leaves with a very blue-grey hue and metallic reflections. In June, light spikes of silver colour, fading to yellow over the summer, emerge from the clump, softening the rigidity of its silhouette.

Hardy down to -20°C and accustomed to dry, poor soils, this fescue thrives in both full sun and partial shade. It will be even bluer in poorer soil.

It makes an excellent alternative to lawn in dry areas, but is also perfect for borders, slopes, rockeries, at the front of flower beds, and even in pots. In the same genus, the Festuca ‘Elijah Blue’ is another small, perennial, evergreen fescue, intensely blue, that thrives everywhere.

You can pair them with other plants that have blue or grey foliage, such as Stachys byzantina, Senecio cineraria, or Salvia argentea. They will look stunning in a contrasting arrangement alongside the santolina with its yellow flowers.

Festuca ‘Intense Blue’

Hosta 'Blue Angel'

Next to the ‘Halcyon’ hosta, which is one of the most famous blue cultivars, Hosta ‘Blue Angel’ stands out among the blue-leaved hostas. Once well established, after about 5 years, it forms very large clumps, reaching 70-80 cm in height and over 1.20 m in width. It displays its large, very blue-grey heart-shaped leaves, which are heavily veined. Its foliage is among the bluest of all. In summer, this clump of leaves showcases spikes of white bell-shaped flowers.

Hardy, this magnificent specimen thrives in shade or partial shade, in any cool but well-drained soil.

It is simply stunning at the edge of woodlands, in rockeries and cool borders, or in a contemporary or Japanese-style bed. It provides contrast with green hostas or ferns with delicate fronds.

Hosta ‘Blue Angel’

Schizachyrium scoparium 'Prairie Blues'

Another interesting perennial grass for the blue colour of its foliage is the Schizachyrium scoparium ‘Prairie Blues’. It develops an upright bush of impressive size, reaching 80 cm to 1 m in height when in flower, with a width of 50 cm. Its soft, linear leaves are very colourful, adorned with a sumptuous, intense blue-silver hue in summer, before turning orange in autumn and then purple in winter. In summer, slender white spikelets, maturing to silver tones, appear above the deciduous foliage. It remains well upright and decorative until the heart of winter.

Cold-resistant and drought-tolerant, it thrives in dry, well-drained, poor soils and is easy to cultivate in full sun.

It excels in dry gardens or poor soils, adding a poetic and colourful touch to borders or large meadows. Pair it with some tall perennials: hollyhocks, Perovskias, Veronicastrums, or Mulleins.

Schizachyrium scoparium ‘Prairie Blues’

Sedum sieboldii

Among the Sedums, some display exceptional colours. This is the case with the Sedum sieboldii, a creeping autumn stonecrop with very attractive deciduous grey-blue foliage. Offering subtle shades, its small, round succulent leaves are marginate, additionally, with Indian pink. It spreads in carpet-like clumps not exceeding 15 cm in height and bears clusters of dark pink globular inflorescences from September to October.

It grows easily in warm situations and in very well-drained soil. Plant it in rockeries or on very exposed slopes alongside alpine plants such as Saxifrages and some elegant grasses that will provide the necessary lightness in contrast, like Stipa gigantea.

Sedum sieboldii

Panicum virgatum 'Dallas Blues'

Here is another large perennial grass that captivates with its very blue foliage, featuring metallic reflections. This Panicum virgatum ‘Dallas Blues’ grows in a graceful large fountain of long, ribbon-like leaves, with a bluish-green hue that deepens throughout the summer. They are streaked with steel-like reflections and gradually take on warm tones in autumn. When mature, it will reach a height of approximately 1.50 m to 2 m in all directions. Its summer flowering is also very attractive, as it emerges in large airy panicles of purplish-pink.

It thrives best in full sun in deep, rich soil, even clayey or calcareous. It can adapt to dry and poor soil, but will exhibit slightly less spectacular growth.

This elegant and highly structural grass will look stunning at the back of slightly wild flowerbeds or even in a large pot on the terrace.

It will create beautiful, lively, and airy masses alongside tall wild asters, such as the Aster turbinellus, which also forms lovely airy bushes.

Panicum virgatum ‘Dallas Blues’

Actaea pachypoda 'Misty Blue'

This perennial of the undergrowth surprises with its beautiful, deeply divided foliage that turns a powdery blue in spring before changing to a bluish green as the season progresses. The Actaea pachypoda ‘Misty Blue’ gradually forms beautiful dense clumps, reaching 60 cm in height and 40 cm in width. Highly decorative and richly coloured, this deciduous foliage is enlivened in spring by lovely pom-poms of starry white flowers. This subtle flowering is followed by astonishing white fruits with red pedicels, providing a striking contrast with the bluish vegetation.

Robust and hardy, this vigorous perennial thrives in shaded situations, in the undergrowth, in fresh to dry, rich soil.

In these cool, dappled environments, it will wonderfully accompany Polygonatum, Epimedium, and ferns with delicately incised leaves.

Actaea pachypoda ‘Misty Blue’