Verbena hastata Blue Spires

Verbena hastata 'Blue Spires' is a variety of verbena that is taller than the species with blue-lilac flowers. It is a large hardy herbaceous perennial with an upright, airy, and transparent habit that easily blends with other larger perennials to bring lightness. Throughout the summer, the tips of its sturdy stems are covered with branching candelabras, densely packed with small, nectar-rich flowers. This plant thrives everywhere, in any well-drained, moist, or occasionally dry soil, in full sun, and it readily self-seeds in the garden.

Native to Canada and the United States, the hastate verbena belongs to the Verbenaceae family and colonises fresh soils, riverbanks, wet meadows, and floodplain forests. The 'Blue Spires' variety is a tall, bluer form of this deciduous perennial. Depending on soil moisture, it can reach up to 1.20 m (4ft) high, with a width of 60 cm (24in). It grows from a fibrous rhizome, rapidly forming an erect, narrow clump of square stems, sometimes branching towards their tips. The leaves are opposite, 10 to 13 cm (4 to 5in) long, 2.5 cm (1in) wide, lanceolate, veined, coarsely toothed, and green. From June to August, the upper ends of the stems branch out and have thin, pointed spikes, 10 to 12 cm (4 to 5in) long, formed by numerous small blue flowers with five petals, 5 mm (0in) in diameter. This is followed by small, hard, elongated fruits containing seeds that readily self-seed. Small colonies of plants, identical to the parent, are produced from the rhizomes.

Verbena hastata 'Blue Spires' is perfect for adding height to borders, and valuable for natural gardens. This perennial is remarkable at the edge of a water feature, in moist soil, planted en masse. In a slightly wild scene, it pairs well with Gauras and grasses (such as small miscanthus, eragrostis, and stipes). It also performs well in drier soil, although it will be smaller. Its light, sculptural spikes contrast with the roundness of roses, complement the Lavenders of the same tone, and beautifully accompany the grey or silver foliage of Artemisias. Hastate verbena can also be used for herbal teas. It is said that our ancestors attributed aphrodisiac properties to it!