Overdam Feather Reed Ornamental Grass – Calamagrostis × acutiflora ‘Overdam’

Description

Calamagrostis × acutiflora ‘Overdam’ is a striking, variegated ornamental grass forming upright clumps of narrow, green leaves finely edged with creamy-white margins. In early to midsummer, tall, airy plumes of purplish-green flowers rise above the foliage, fading to a warm golden tone as they mature. The flower stems remain attractive throughout autumn and into winter, providing valuable structure and texture.

Growth & Habit

‘Overdam’ is a compact and clump-forming grass with a neat, vertical habit. Typically reaches around 120–150 cm in height when in flower and 50–60 cm in spread. It is non-invasive and maintains a defined outline, making it suitable for formal or naturalistic designs.

Conditions

• Position: Full sun to light partial shade
• Soil: Moist but well-drained; tolerates clay, loam, and sandy soils
• Aspect: Prefers open, sunny conditions with good air circulation
• Hardiness: Fully hardy in the UK (H7)

Seasonal Interest

Emerges in spring with fresh, variegated foliage. Tall flower spikes appear from June to August, ageing beautifully through autumn. The dried plumes remain decorative through winter, adding architectural form and movement to the garden.

Maintenance

Cut back to the base in late winter or early spring before new growth begins. Remove any spent flower stems and old foliage to maintain a tidy habit. May be divided every few years in spring to rejuvenate growth and control clump size.

Note: As a deciduous grass, ‘Overdam’ dies back in winter before re-emerging in spring. Growth rate and appearance may vary slightly with soil type and local conditions.