Colonial Bentgrass
Agrostis capillaris
Poaceae · grass grasslike · introduced
Historically common in western WA lawns, often present as an uninvited but well-adapted component. Naturally suited to the acidic, moist soils of the Puget Sound lowlands. Seed alone at 2 lb/1000 sqft or mix with Chewings fescue (0.5 lb bentgrass + 2.5 lb fescue). Requires more intensive mowing management than other lawn species but rewards with a very fine-textured, dense turf.
Plant Profile
Size & Form
Height
4-12 in
Spread
Spreads by short stolons; forms a dense, fine-textured mat
Growth Rate
Moderate
Site Requirements
Light
Sun to Part Shade
Soil Drainage
Moist
Soil pH
5.0-6.5
Water
Moderate
Drought Tolerance
Low
Hardiness
Zones 4a–8b
Ornamental Interest
Bloom Time
mid summer
Origin
Europe
Diseases: Regionally Documented (1)
Diseases: Other Associations (3)
Pests: Other Associations (1)
Phenological Calendar
View full calendar (5 stages)
| Stage | Typical Window |
|---|---|
| Spring green-up BBCH 09 | Feb 1-Feb 28 |
| Active vegetative growth BBCH 21 | Mar 1-Apr 15 |
| Peak spring growth BBCH 39 | Apr 15-Jun 15 |
| Summer stress period BBCH 45 | Jul 1-Aug 31 |
| Winter semi-dormancy BBCH 97 | Nov 15-Feb 1 |
Cultivars (1)
'General category'
Colonial bentgrass (A. capillaris) should not be confused with creeping bentgrass (A. stolonifera), which is used on golf greens and requires even more intensive management. Colonial bentgrass is the species historically used in western WA home lawns and is well-adapted to the maritime climate.
Commonly invades other lawn types in western WA due to favorable climate; can be managed as the desired species rather than treated as a weed
Data Maturity Baseline Extension data. Expert review underway.