Grass - Calamagrostis acutiflora 'Overdam'

While ornamental grasses do not typically attract pollinators, Calamagrostis 'Overdam' provides habitat and shelter for beneficial insects and small wildlife. Birds may also use the tall, sturdy flower spikes for perching, and the dried seed heads can provide food for birds in the fall and winter months.

Deciduous; the foliage dies back in winter and regrows in spring.

• Flowering Season: Late spring to summer (June-July)

– Specimen or accent plant for variegated foliage interest

– Mixed perennial borders or cottage gardens

– Urban and courtyard gardens

– Mass plantings for light texture and movement

– Containers and narrow garden beds

– Winter interest and structure

The leaves of 'Overdam' are narrow, arching, and variegated with green centers and creamy white margins. The variegation provides a striking contrast that adds brightness and movement to garden beds or borders. The foliage remains fresh and upright throughout the growing season, making it an ideal choice for adding structure and texture.

Overdam produces tall, feathery, wheat-colored flower spikes that rise above the foliage. The flowers emerge greenish-pink and gradually turn golden as they mature, remaining attractive throughout the summer and into fall. The flower spikes can be left standing for winter interest.

• Planting Season: Best planted in spring or early fall when temperatures are cool, allowing the grass to establish roots before the growing season or winter dormancy.

• Soil Requirements: Prefers well-drained, moderately fertile soil. It tolerates a range of soil types, including clay and sandy soils, but performs best in evenly moist, well-drained locations.

• Spacing: Space plants 2-3 feet apart to allow for mature spread and to create a natural, flowing look.

Planting Instructions:

1. Dig a hole twice as wide and as deep as the root ball.
2. Place the grass in the hole with the top of the root ball level with the soil surface.
3. Backfill with soil, tamp gently, and water thoroughly.
4. Apply mulch around the base to retain moisture and suppress weeds.

Pruning is minimal for Calamagrostis 'Overdam'. Cut back the foliage to about 4-6 inches above the ground in late winter or early spring before new growth begins. This helps to remove any dead or damaged leaves and makes way for fresh spring growth. The dried flower spikes can be left standing through winter for added interest or removed in early spring.

Overdam prefers moderate watering, especially during the first growing season to establish a strong root system. Water regularly during dry periods, ensuring the soil stays evenly moist but not waterlogged. Once established, it can tolerate short periods of drought but performs best with consistent moisture.

Thrives in full sun to partial shade. For the best growth and variegation, plant Overdam in a location that receives at least 6 hours of direct sunlight per day. It can tolerate light shade, but full sun encourages the strongest color and upright form.

The tall, feathery flower spikes of 'Overdam' are ideal for use in fresh or dried floral arrangements. Harvest the flower spikes when they are fully developed for the best results. The variegated foliage can also be used to add texture and color to cut arrangements.

Fertilize in early spring with a balanced, slow-release fertilizer or organic compost to encourage healthy growth and vibrant foliage. Avoid over-fertilizing, as this can lead to excessive growth that may cause the grass to flop. A second light application of fertilizer in mid-summer can help sustain growth through the season.

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

• Pest and Disease Resistance: Overdam is generally resistant to pests and diseases. It is a low-maintenance plant that thrives with little intervention. Ensure good air circulation to prevent fungal issues, especially in humid conditions.

• Winter Care: In colder climates, the foliage will die back in winter but can be left standing for visual interest. Cut back the foliage in late winter or early spring to prepare for new growth.

– Wind-pollinated (anemophilous)

– Flowers are not attractive to bees or butterflies

– Like 'Karl Foerster', it is generally a sterile cultivar – does not self-sow

– Propagated by division rather than seed

– Heuchera (Coral Bells) – colorful foliage complements the variegated leaves of 'Overdam'

– Geranium (Cranesbill) – sprawling habit contrasts well with vertical grass form

– Salvia nemorosa – upright flower spikes pair well with fine grass texture

– Echinacea (Coneflower) – summer blooms and strong stems complement grass's verticality

– Sedum (e.g., ‘Autumn Joy’) – late-season interest and contrasting forms

– Lavandula (Lavender) – drought tolerance and color pairing in sunny gardens

– Nepeta (Catmint) – blue flowers and mounding habit soften grass edges

– Allium (Ornamental Onion) – round blooms and architectural shape contrast with the grass's form