Yorkshire fog is a common UK grass that flowers between May and July.
Yorkshire fog, botanically known as Holcus lanatus, has soft hairy leaves which give rise to its other common name ‘velvet grass’ and its flowering plumes are often purple tinged, which can form an amazing haze of colour across a large area.
Its unique identifying feature can be seen by peeling back leaves at the base of the stem to reveal its pink striped fleshy stem- ‘stripy pyjamas’.
It prefers damp ground and is often seen around drainage ditches and waste ground. It produces a large amount of seed and is a rapid coloniser and is rarely eaten by grazing animals so it can grow very rapidly.
It can sometimes be confused with creeping soft grass, Holcus mollis, which looks similar but has ‘hairy knees’ at junctions along the stem.
Some caterpillars use it as a food plant, for example the speckled wood and small skipper butterflies.