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Plant of the month: April

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Gardens

RHS Garden Rosemoor

Harlow Carr | Hyde Hall | Rosemoor | Wisley |

RHS Garden Rosemoor

Plant of the month: April

Mysosotidium hortensia flowers. Photo: Stephen Record. Copyright RHS.

Name: Myosotidium hortensia
Common name: Chatham Island forget-me-not
Family: Boraginaceae

Vital statistics
Height and spread: 60cm (2ft) x 60cm (2ft)
Form: Evergreen perennial
Soil: Humus-rich, moist but well-drained
Aspect: Light dappled shade
Hardiness: Half hardy

Myosotidium hortensia @ Rosemoor

This fabulous plant, with its huge, shiny, deeply veined leaves and large, pale to dark blue forget-me-not flowers, has now thrived with other borderline tender subjects for several years in the warm, sheltered conditions of The Old Kitchen Garden to the rear of Rosemoor House in Lady Anne's Garden.

Myosotidium

This genus contains one species of evergreen perennial from the wet, windswept Chatham Islands off the east coast of New Zealand.

It has thick, fleshy stems and leaves; the leaves are mid-green, simple and glossy and look rather like small rhubarb leaves.

The flowers are like those of a forget-me-not.

Myosotidium hortensia

This plant is clump forming, with impressive, very glossy, heart-shaped, deeply ribbed, basal leaves, up to 30cm (12in) long, with wavy margins.

The flowers, borne in early summer, are dense heads of bell-shaped, pale to dark blue flowers, 1cm (0.5in) across, sometimes with white margins.

This plant can be difficult to grow as it needs mild, cool, damp conditions, preferably near the coast. However, it would look impressive in a large rock garden or herbaceous border, given the right conditions.

In frost-prone areas it requires the protection of a cool greenhouse.

Myosotidium hortensia at Rosemoor.  Photo: Stephen Record. Copyright RHS

Cultivation

Grow in humus-rich, moist but well-drained, gritty soil, with shelter from cold, drying winds. Provide with a seaweed mulch.

Under glass, grow in loam-based potting compost in bright filtered light. Water freely during the growing season and apply a seaweed-based fertiliser. Keep just moist in winter.

Prone to slugs and aphids.

Propagation

Sow seed under glass in autumn or as soon as ripe.