Redtop

Credit: 
Percy Folkard
Credit: 
JRJ
Scientific name: 

Agrostis gigantea Roth

Type: 
Agronomic Grass
Annual precip. min (mm): 
450
Seed size: 
Small
Seeds per kg: 
10,670,000
PR Suitability note: 
Redtop is well suited to the Peace region.
Key considerations: 
Used for rehabilitation of disturbed sites with high acidity or heavy metal contamination. Some use for pasture and hay in wet meadows, although palatability and nutritional value for livestock is low compared to other species.
General Description: 

Redtop is a long-lived, perennial tufted grass with common names like bentgrass or ticklegrass. Several closely related species of this bentgrass group are discussed in the literature including redtop (Agrostis gigantea Roth or Agrostis stolonifera - introduced), and hair bentgrass (Agrostis scabra - native). The common name ticklegrass can refer to any of these species. Redtop was introduced and has become naturalized throughout British Columbia. It is abundant following disturbance, especially in the northeastern part of British Columbia.

Its roots are tough and extensively branched with scaly rhizomes. This species was formerly combined with Agrostis stolonifera under the name Agrostis alba, but it is distinguished from Agrostis stolonifera by its underground rhizomes and tolerance of drier areas. Redtop forms a dense sod, but not as compact as bluegrasses.

Its stems grow 20 to 120 cm (8 to 47 in.) high. Leaves are smooth, 4 to 10 cm (1.5 to 4 in.) long and 3 to 8 mm wide.

Seed heads form open panicles with spikelets that are awnless or rarely with short awns. Redtop reproduces from both seeds and rhizomes.

Origin: 
Introduced from Europe.
Distribution: 
Naturalized throughout British Columbia.
Habitat and climate: 
Grows on dry to wet roadsides, fields, or waste areas in lowland and montane areas.
Uses: 
Introduced initially for use in lawns and turf grasses. Used for erosion control in riparian areas and wetlands, and rehabilitation of disturbed sites with high acidity or heavy metal contamination. There has been some use for pasture and hay in higher elevation wet meadows in western states.
Recovery after use (rating): 
L
Recovery after use: 
Tolerant of grazing because of semi-prostrate growth and generally low palatability.
Forage yield (rating): 
L
Palatability/Nutritional Value: 
LowCattle prefer most other agronomic species over redtop. When it is available it is preferred by cattle and horses in spring and summer, preferred by sheep in spring, and desirable in summer.
Longevity (rating): 
H
Persistence (rating): 
H
Invasiveness (rating): 
H
Invasiveness: 
Very aggressive even on very acid soils.
Erosion control (rating): 
H
Drought tolerance (rating): 
M
Soil texture preference (rating): 
F
Soil texture preference: 
Grows well on poor, clayey soils, on poorly drained soil and on soils with low fertility. Not suited to limestone based soils.
Flooding tolerance (rating): 
M
Salinity tolerance (rating): 
L
Acidity tolerance (rating): 
H
Acidity tolerance : 
Grows well on very acid soils.
Ease of establishment (rating): 
M
Application requirements: 
Early spring seeding is recommended to allow establishment before onset of drier conditions. Broadcast seeding with light harrowing is suitable. Soil compaction over seed may cause crusting which can be impenetrable to emerging seedlings.
Suggested mixtures: 
Seldom seeded alone and forage quality is improved when seeded with species such as timothy and/or clover species.
Management considerations: 
This species should not be seeded where native vegetation is desired, and readily hybridizes with other Agrostis species. Pasture mixes will need to be grazed closely to allow for palatable regrowth on wetter and sub-irrigated sites.