The genus Anchusa provides some of the truest blues you will find in the garden, vivid shades that make them pop out of the back of the border. They are highly attractive to bees and butterflies and suit mixed borders, cottage gardens and Mediterranean gardens. There are annual, biennial and perennial types that need a little care, but they are worth it because they are not just an ornamental plant but are also edible and can be used as cut flowers.
Part of the Boraginaceae family, they have distinctive hairy stems and leaves. Flowers can be white, yellow, blue or violet, but are commonly blue. The most used garden species is A. azurea, a tall plant that has produced many cultivars.
The most popular variety is ‘Loddon Royalist’, which produces deep-blue flowers and is a Chelsea favourite. The varieties ‘Dropmore’ and ‘Feltham Pride’ are also rated. Grown from seed they are more variable than ‘Loddon Royalist’, which is propagated by root cuttings.
There is one anchusa used as a bedding plant, A. capensis from South Africa. It is a low-growing plant, reaching just 20cm, but produces masses of vivid blue flowers. ‘Blue Angel’ is a recommended variety, useful for filling gaps left by early-flowering perennials. There is also an alpine species, A. caespitosa, which hails from Crete. It is a lovely prostrate perennial with deep-blue flowers and white centres.
The taller species A. azurea and ?A. officinalis are ideal for mixed or herbaceous borders and prefer deep, fertile, well-drained but moisture-retentive soils in full sun. They may need to be staked. Deadheading is advisable because they can self seed and become invasive.
When the foliage becomes unsightly they are best cut back hard. Doing so by early autumn actually helps them get through the winter. There is less to rot off, which is sometimes a problem. Mulch just the root zone rather than the crown to prevent this. Even so, they tend to be short-lived perennials.
A. capensis is a biennial so can be grown as a pot plant, overwintered and planted out. However, in the UK it is possible to sow it as annual in April. They look lovely at the front of a border or as part of a mixed display in a large container. They are highly drought-tolerant so do well in well drained soil and full sun.
A. caespitosa is hardy to -15°C so can be planted in the rock garden and likes a gritty soil. However, some like to show them off in an alpine house, in which case they need a deep pot with equal parts loam, leaf mould and sharp sand.
What the specialists say
Kevin Marsh, grower, ?Beeches Nursery, Essex
"Anchusa are very short-lived perennials, often behaving annually in heavy soils. They demand a very light, sandy, free-draining soil in full sun. The only way I have found to keep them perennial is to cut them back completely to the ground, straight after flowering, so they develop a basal rosette on which to overwinter. Even then disease can strike and rot the crown readily.
"‘Loddon Royalist’, the most popular variety, is propagated by root cuttings. ‘Dropmore’ and ‘Feltham Pride’ are also seen but are seed strains so always a little variable. ‘Opal’ can be found but is less popular as it is wishy-washy sky-blue.
"Other species like undulata need a cold greenhouse and often flower through the winter. A. capensis is a South African biennial, sometimes grown as an annual in the UK. The form ‘Blue Angel’ is sometimes sold by seed companies but differs little from the species and really needs a cold greenhouse at least."
Emily Darby, horticultural consultant, ED Hort Projects, ?Berkshire
"Anchusa is a good plant for getting that strong, clear blue into a scheme. I haven’t used it much recently but remember it looking great in the spring, although going black and dying off later on in the season — a bit like forget-me-nots do — leaving an unsightly gap.
"The famous variety ‘Loddon Royalist’ was bred at Loddon Nursery near me in Berkshire. In fact, I worked at the Big Plant Nursery, which was built on the same site. It’s a popular variety for good reason. It has strong, tough stems that don’t need to be staked along with deep rich-blue flowers. ?It is often seen gracing the show gardens at the RHS Chelsea ?Flower Show.
"It’s not just valuable in the garden either. The flowers are edible and can be used to brighten up salads or, even more of a novelty, frozen inside ice cubes."
Species and varieties
A. azurea, the garden anchusa, is an herbaceous perennial with lance-shaped, coarsely hairy, mostly basal leaves. Erect branching stems with bright gentian-blue flowers, ageing to blue/purple. Height: 90cm.
A. azurea ‘Dropmore’ is a lovely variety that produces vivid blue flowers between May and July. Grows easily from seed and makes a good garden plant and cut flower. Height: 90cm.
A. azurea ‘Feltham Pride’ is a moderately compact Italian bugloss that produces numerous azure blue flowers on bushy, coarsely foliated plants from early to midsummer. Height: 60-90cm.
A. azurea ‘Little John’ is a dwarf variety with coarse, grey/green leaves and deep-blue, long-lasting flowers. Height: 45cm.
A. azurea ‘Loddon Royalist’ is an herbaceous perennial with coarsely hairy, lance-shaped, mostly basal leaves. It produces strong, erect, branching stems with intensely deep-blue flowers. Height: 1.5m.
A. azurea ‘Opal’ is a nice variety that produces pale-blue flowers in early summer. Quickly forms a good clump. Height: 90cm.
A. capensis ‘Blue Angel’ is a bushy dwarf annual variety that has dark-blue flowers and narrow hairy leaves. Height: 20cm.
A. caespitosa is an alpine species that forms prostrate rosettes of linear-lanceolate bristly green foliage. Good in rock gardens, raised beds or alpine house. Height: 5cm.
A. officinalis, the common bugloss or alkanet, is an upright perennial or biennial with hairy lance-shaped leaves and stems. Produces many spikes of attractive blue flowers from summer through autumn. Not to be confused with the similarly invasive Pentaglottis sempervirens (green alkanet). Height: 30-80cm.
Thank you to Floramedia, which supplied the images for this article from its photo library