Feather Reed Grass

Feather Reed Grass, or Calamagrostis × acutiflora ‘Karl Foerster’, is a striking, upright ornamental grass known for its narrow green foliage and tall, feathery flower plumes that appear in early summer and persist well into winter. Perfect for garden borders and pots, providing year-round interest to your outside space.

Providing seasonal care is essential to maintain its tidy habit, strong growth, and year-round interest. Below is a complete seasonal care guide for Feather Reed Grass throughout the year.

Spring

Pruning and Maintenance

In early spring, cut back all old foliage and stems from the previous season to just above ground level using clean, sharp secateurs. This allows fresh new growth to emerge and keeps the plant looking neat.

Feed

Apply a light dressing of a balanced, slow-release fertiliser or compost in spring. Avoid overfeeding, as excessive nutrients can cause floppy growth.

Dividing (if necessary)

Every 4–5 years, Feather Reed Grass can be divided in spring if clumps become overcrowded. Lift the clump carefully, divide into sections, and replant into well-drained soil with adequate spacing.

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Begin regular watering as temperatures rise, keeping the soil lightly moist while new growth establishes.

Summer

Pruning and Maintenance

Minimal pruning is required during summer. Allow the flower plumes to develop fully, as they provide the main ornamental feature of the plant.

Mulching

Apply a 2 to 3-inch layer of organic mulch around the base of the plant to retain moisture, suppress weeds, and regulate soil temperature.

Watering

Feather Reed Grass is drought-tolerant once established but benefits from watering during prolonged dry spells, especially in its first year. Allow the soil to dry slightly between waterings.

Autumn

Pruning and Maintenance

Leave the flower heads and foliage intact through autumn for continued structure and movement in the garden. Avoid cutting back at this time.

Protection from frost

No special frost protection is required, but a mulch helps improve soil condition and protect roots.

Winter

Pruning and Maintenance

Avoid cutting back Feather Reed Grass during winter. Leave the dried stems and flower plumes in place, as they provide structure, winter interest, and help protect the crown from cold and wet conditions. Major pruning should be carried out in early spring before new growth emerges.

Protection from frost

Feather Reed Grass is fully hardy and withstands winter conditions well. The dried stems help protect the crown from cold and wet.

Pest and disease prevention

Pests and diseases are rarely an issue, but inspect occasionally for signs of rot caused by poor drainage and remove any affected material promptly.

Plant SOS

Floppy growth – A sign of overly rich soil or too much shade. Reduce feeding and move to a sunnier position.

Poor flowering – A sign of insufficient light. Plant in full sun for best results.

Yellowing foliage – A sign of poor drainage or water-logging. Improve drainage and reduce watering.

Sparse growth – A sign the plant needs dividing. Divide mature clumps in spring.

Weak establishment – A sign of competition from nearby plants. Improve spacing and airflow.

Holes in leaves – A sign of slug and snail damage. Use Slug and Snail repellent or Slug and Snail control.