Grass Species Characteristics

Currently, throughout the UK, most reseeds are a mixture of diploid and tetraploid perennial ryegrass.

There are also other types of ryegrass and species used such as clovers, Timothy, cocksfoot, and in recent years Festuloliums, which all have a role to play in certain situations.

Each of these species have different growth and quality characteristics so it is important to select the most appropriate species for your ground and situation.

Compared to modern day ryegrasses, these weed grasses will produce lower yields and lower quality forage. The palatability and digestibility will also be poorer which will all result in a reduction in animal performance and profitability from home grown forage.

Perennial ryegrass

Lolium perenne (PRG)

The most widely sown species and most persistent type of ryegrass. It is a versatile species as it can be cut or grazed. Different varieties of perennials are subdivided into diploids and tetraploids and then divided further into early, intermediate or late – meaning that they provide grass growth at different times of the growing season.
It yields around 13-15t DM/ha, which is lower yielding than Italian ryegrass but perennials last longer than Italian ryegrass and westerwolds, at around five to seven years (depending on heading date).

Italian ryegrass

Lolium multiflorum (IRG)

This is a short-lived grass, lasting for two years. It will start to grow when the soil temperatures reach 3˚C, therefore growing earliest in the spring and latest in the autumn compared to other agricultural grasses. Italian ryegrass is very good at utilising any residual nutrients left within the soil after the previous crop has been harvested. 
It has a very open growth habit, with fewer tillers than other grasses and is best suited to cutting rather than grazing regimes. This is one of the highest yielding grass species available in the UK and can provide around 18t DM/ha/year in the correct conditions.

Hybrid ryegrass

Lolium multiflorum x Lolium boucheanum (HRG)

Hybrid ryegrass is a cross between Italian and perennial ryegrasses. The crossing between the two species means it has the yield of IRGs and the longevity of the PRGs, so the persistency will be around 4 years. Most varieties have more Italian genes within the plant, making it a useful inclusion in intensive mixtures. Hybrids also have more tillers than straight Italian ryegrasses due to the perennial gene within the plant, which increases ground cover and also makes them suitable for grazing.

Timothy

Phleum pratense

Timothy grows at lower temperatures than perennial ryegrasses and can be good for early grazing in cold late springs. It has good ground cover and is a winter hardy species, which thrives on wet or heavy land. It is a very common species found in pasture throughout the UK.
This is mainly due to its ability to provide good mid-season growth which can fill the summer gap when ryegrass growth is slowing down. Timothy is suited for both cutting and grazing.

Westerwold ryegrass

Lolium multiflorum westerwoldicum

The only agricultural grass to produce a stem and a seed head from a spring sowing. This makes it ideal for hay production or increasing silage yields if spring reseeding. These are annual grasses which are very fast to establish but are relatively short lived. Westerwolds are very good at utilising any residual nutrients left within the soil after the previous crop has been harvested.

Festulolium

Festulolium is a cross between meadow fescue (Festuca pratensis) or tall fescue (Festuca arundinacea) and perennial ryegrass (Lolium perenne) or Italian ryegrass (Lolium multiflorum). When the cross is done, it will result in grasses with the best characteristics of each parent. Depending on parental material, a Festulolium will get the best qualities from both grasses but it will be somewhat more similar to either the fescue or the ryegrass type. Hence, Festuloliums can be categorized into two main types – the tall fescue or the ryegrass type – related to their characteristic and phenotypic appearance.
It is characterised by high dry matter yield, high cold tolerance, drought tolerance and the overall high persistency that tends to be found in fescues, whereas its rapid establishment, spring growth, good digestibility, high sugar content and palatability, characterise ryegrass.