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Sowing & Growing: Perennial Ryegrass

Perennial ryegrass (Lolium Perenne) is the most commonly grown grass, particularly in grazed/clover leys. This is a long term species, the most persistent of the ryegrasses and usually lasts up to 6 years. After which productivity may start to drop off and native weed grasses may creep into the sward.

Perennial ryegrass lasts considerably longer than the higher yielding Italian and westerwold ryegrasses. It’s flexible in use, being used in grazing or cutting and made into silage, haylage or hay later in the season. It is a very popular grass for long term mixes.

When to sow: Ideal times are April to September when there is adequate moisture for establishment.

Sowing Rates: 3.5 g/m2 - 14kg per acre - 35kg per ha

Preparation: The best results for establishing a grass ley are achieved by starting from scratch with a clean, weed free seed bed. The seed bed should also be as fine as possible. Achieved by ploughing or cultivating, depending on machinery available.

Sowing: Drill or broadcast into a fine, firm seedbed and try to avoid drying the soils out with excessive cultivations in dry autumns. Rolling to retain moisture and break down clods before and after sowing with a cambridge or flat roller is essential. Broadcast seed should be harrowed lightly after sowing and before rolling.

Management: Cutting for silage will depend on the heading date of the plant, each ryegrass species is different in terms of its maturity. Generally most perennial ryegrasses fall into intermediate or late varieties. Intermediate varieties will head around the last week of May. Late varieties will head in early June. As the plant starts to mature and develop a seed head the quality of the forage (D-value) will decline. 

A D-value between 67-70 will provide good quality forage, which equates approximately to 25-50% ear emergence. When the plant is cut will depend on the type of stock the forage is to be fed to. Some stock require a lower quality, stemmier silage such as dry cows, while growing young stock requires a higher quality forage. 

Perennial ryegrass normally provides 2 cuts on good ground, or a cut and aftermath grazing depending on the mixture. This species produces more leafy tillers from the base of the plant than other ryegrass species, which means it produces a better, thicker grazing sward. 

Grazing the sward in mid to late autumn is important because it stops the crop going into the colder winter temperatures in an upright leafy state, where it can be affected by hard frosts. Grazing also allows the base of the sward to be cleaned out by the livestock and fresh growth encouraged early next spring. 

Date Posted: 10th February 2023