Grass
Feather Reed Grass
Calamagrostis x acutiflora 'Karl Foerster' · Poaceae
Also called: Karl Foerster Feather Reed Grass, Karl Foerster Grass
Feather Reed Grass (Calamagrostis x acutiflora 'Karl Foerster') is a moderate-water grass well suited to Tucson and the low desert.
Feather Reed Grass at a glance
- Water use
- Moderate (established)
- Sun
- Full sun in mild climates, but in Tucson give it morning sun with afternoon shade; it is a cool-season grass and struggles in full all-day low-desert summer sun
- Mature size
- Foliage 2-3 ft; stiff vertical flower stalks reach 4-5 ft tall; clump 1.5-2 ft wide
- Growth rate
- Moderate; clumping and well-behaved
- Bloom
- Pinkish-bronze plumes maturing to golden-tan, narrow upright wheat-like spikes, Late spring to early summer (earlier than warm-season grasses), with feathery plumes maturing to narrow wheat-colored spikes that persist into fall
- Cold hardiness
- Cold hardy to about USDA zone 4-5; fully hardy in Tucson. Semi-evergreen to deciduous depending on winter.
- Soil
- Tolerant; prefers moisture-retentive, fertile soil but handles clay and alkaline pH. Avoid sites that bake dry.
- Native range
- Garden hybrid (C. arundinacea x C. epigejos) of Eurasian parentage; named selection
- Best used as
- Strong vertical accent, Narrow upright screen or rhythm in borders, Mass planting for movement, Cut/dried arrangements
- Wildlife
- Vertical seed spikes offer cover and winter structure; minor bird value. Deer-resistant.
- Toxicity
- Non-toxic to dogs, cats, and humans. A sterile hybrid that sets no viable seed, so it is non-invasive.
How to grow Feather Reed Grass in Tucson & the low desert
Watering
Cool-season grass that wants more consistent moisture than warm-season grasses. Water deeply 2 times per week through Tucson's summer (it semi-rests in extreme heat) and weekly in spring/fall; do not let it dry out completely. Keep evenly moist the first year.
Fertilizer & nutrients
Light to moderate feeder. Apply balanced slow-release fertilizer in early spring; a second light feeding in fall supports cool-season growth. Compost-amend the planting hole in Tucson's alkaline, low-organic soil.
Pruning & care
Cut back to 4-6 inches in late winter (January-February) before its early-spring flush. Because it is cool-season, it greens up and blooms earlier than warm-season grasses.
Notes
Sterile, so no reseeding worries. The main Tucson caveat is heat: as a cool-season grass it performs best with afternoon shade and steady moisture, and may look tired during the hottest July-August stretch before reviving in fall. Sited in an east exposure or filtered light, it is a reliable architectural grass.
Sources: Missouri Botanical Garden Plant Finder; University of Arizona Cooperative Extension / Pima County Master Gardeners; AMWUA; North Carolina Extension Gardener Plant Toolbox