Perennial Ryegrass

Credit: 
Percy Folkard, BC FLNR
Credit: 
JRJ
Scientific name: 

Lolium perenne L.

Type: 
Agronomic Grass
Annual precip. min (mm): 
400
Annual precip. max (mm): 
600
Seed size: 
Medium
Seeds per kg: 
501,000
PR Suitability note: 
Perennial ryegrass is sometimes grown in the Peace Region, although some varieties may not be long lived. Choose a variety that known for its winter-hardiness, and consider seeding objectives.
Key considerations: 
Slightly less aggressive growth than Italian ryegrass. Since it is short-lived in the Peace, it can be used as short-term cover (similar to Italian ryegrass) while other species establish.
General Description: 

Perennial ryegrass is a short-lived, perennial, cool season bunchgrass. It is closely related to Italian ryegrass, but is smaller, has folded rather than rolled leaves, and lacks awns. Perennial ryegrass produces a shallow, fibrous root system, with the majority of roots in the upper 15 cm (6 in.) of soil. It tillers freely and produces a dense sod.

Perennial ryegrass produces a dense cover of low-growing leaves, and stems that are up to 60 cm (24 in.) long with a slender spike up to 30 cm (12 in.) long. Leaves are dark green, narrow, hairless, keel-shaped, and folded when young. Lower surface is glossy and smooth, while upper surface is veined and duller coloured.

There are diploid and tetraploid genetic types (double chromosome types often associated with more vigorous growth but less hardiness) with a tremendous variation in seed size both between and within genetic types.

Origin: 
Originates in Europe, and is sometimes called English ryegrass.
Distribution: 
This introduced species grows well in southern British Columbia.
Habitat and climate: 
Perennial ryegrass is best suited to areas with cool summers of reasonable moisture without summer drought, and mild winters. May have broader range of application when used as short lived (annual or biennial) for erosion control.
Uses: 
Seed size can be quite variable between and within diploid and tetraploid types. Perennial ryegrass grows quickly so it is well suited for use in pastures, usually under short-term intensively managed grazing and irrigated pastures. It is used for dairy silage, for turf (depending on variety), and for conservation purposes.
Optimal time of grazing use: 
Perennial ryegrass produces high quality forage but requires good fertility.
Recovery after use (rating): 
H
Recovery after use: 
Can be frequently grazed close to the ground, and is adapted for either continuous or rotational grazing systems.
Palatability/Nutritional Value: 
Very palatable as perennial ryegrass can be one of the highest quality forage grasses for grazing. Precautions need to be taken to test for endophytes and a toxin called lolitrem B, especially if feeding perennial grass seed straws from varieties favoured by the turf industry.
Longevity (rating): 
L
Persistence (rating): 
L
Persistence: 
Persistence has been improved by crossing perennial ryegrass with tall or meadow fescues.
Invasiveness (rating): 
L
Competitiveness (rating): 
H
Erosion control (rating): 
H
Erosion control: 
Used often in turf and conservation mixes because of its quick green growth and ground cover, early in the year of establishment.
Drought tolerance (rating): 
L
Drought tolerance: 
Very intolerant of drought or high temperatures.
Winter hardiness (rating): 
L
Winter hardiness: 
Extreme variation in winter hardiness among varieties.
Soil texture preference (rating): 
FM
Flooding tolerance (rating): 
H
Salinity tolerance (rating): 
L
Acidity tolerance (rating): 
H
Fire tolerance (rating): 
H
Ease of establishment (rating): 
H
Ease of establishment: 
Perennial ryegrass is easy to establish but somewhat less aggressive than annual or Italian ryegrass.
Application requirements: 
Seed into a firm fine seedbed, with uniform shallow depth. It is possible to get good establishment with broadcast methods if they are followed by a roller packer.