Perennial ryegrass (Lolium perenne) is a cool-season grass commonly used for lawns, pastures, and turf because of its fast growth and durability. It is part of the Poaceae family and is a well-known source of seasonal allergens. During its pollination period—usually late spring to early summer—it releases airborne pollen that can cause allergic reactions such as hay fever and asthma in sensitive individuals. The allergenic potential of perennial ryegrass makes it an important component in inhalant allergy testing panels.
It can cause seasonal allergic rhinitis (hay fever), with symptoms such as sneezing, nasal congestion, itchy eyes, and sometimes breathing difficulties or asthma.
Its pollination usually takes place from late spring to early summer, although the timing can vary depending on the local climate.
Yes, it contains similar allergenic proteins to other grasses, so individuals allergic to one type of grass may also react to others.