Variety traits

Winter hardiness — perennial ryegrass

Lolium perenne L.

The winter hardiness of perennial ryegrass is limited by the shallow depth of the tillering node and susceptibility to temperatures below -20 °C in the absence of snow cover. The crop's low adaptability to severe winters leads to stand thinning and reduced longevity of the sward.

In the reference 120 varieties crop Perennial ryegrass, where this is mentioned in the description.

A critical factor in the winterkilling of perennial ryegrass is the location of the tillering node at a depth of only 8–13 mm from the soil surface, a depth which tends to decrease as the stand matures. The crop does not tolerate snowless winters or late spring frosts well, which can lead to mass plant loss in unfavorable conditions as early as the first year of growth.

In breeding and variety testing, winter hardiness is assessed visually on a 5-point scale before winter dormancy and after spring regrowth. Additionally, instrumental methods are used, such as counting shoot density per unit area after wintering or laboratory freezing of plants in chambers followed by an assessment of the percentage of surviving shoots 14 days after thawing.

Due to its lower winter hardiness compared to other forage grasses, such as fescue, perennial ryegrass is often used in grass mixtures in limited proportions (no more than 25–30%) to prevent total loss of cover in the event of plant death. Its tendency to winterkill must be taken into account when planning the longevity of pastures and turf covers.

General information about the subject — on the page Winter hardiness.

Sources8

Varieties of Perennial ryegrass mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.