Dr. Phyto

Red fescue

Festuca rubra

Diseases & pests on this plant

• red thread (lawn disease)Laetisaria fuciformis

  Irregular patches of bleached, straw-pink grass from a few cm to ~25 cm across; close up, tiny coral-pink to red gelatinous threads and branching needles bind the dead leaf tips together — the diagnostic sign; in damp weather a faint pink cotton-wool web may show. Grass is killed only at the leaf, not the root, so the lawn recovers.

• pink snow mouldMicrodochium nivale

  Patches of dead seedlings emerging after snowmelt, pinkish-white fluffy mycelium covering plants in cold humid mornings, surviving plants are stunted with brown crown rot.

• dollar spot (lawn disease)Clarireedia jacksonii

  Small, round, straw-coloured sunken spots about the size of a coin (2–6 cm) that can merge into larger bleached patches; individual grass blades show a light tan lesion with a darker reddish-brown band right across the leaf; in early morning dew a fine white cobwebby mycelium can be seen. Most common on fine turf in warm days with cool dewy nights.

• leatherjackets (crane fly larvae)Tipula paludosa

  Yellowing, thinning and dead patches of lawn that lift easily because the roots have been eaten; greyish-brown, legless, tough-skinned grubs up to ~3 cm ("leatherjackets") are found in the top few cm of soil when you lift a patch; birds, badgers or foxes tear up the turf to feed on them; damage peaks in spring as overwintered larvae feed.

• Moss invasion (lawn)Lawn moss invasion

  Soft, low cushions of green to yellow-green moss spread between the grass plants, especially in shaded, damp, compacted or poorly drained areas and under trees. The grass thins out, the surface feels spongy, and in winter the moss can dominate large patches, often where the lawn is mown very short.

• Drought dormancy (lawn)Lawn drought dormancy

  Large, irregular areas of the lawn turn uniformly straw-yellow to tan during hot, dry spells, usually starting on the sunniest, most exposed parts and over sandy or shallow soil. Footprints stay visibly pressed in (loss of springiness), but the crowns at the base of the plants remain alive and the grass greens up again after rain.

• Dog urine scorch (lawn)Lawn dog urine scorch

  Small round patches of dead, straw-brown grass, typically a hand-span wide, each surrounded by a ring of unusually lush, dark-green grass that grows taller and faster than the rest. Patches appear where a dog repeatedly urinates, often near paths, posts or the edge of the lawn.

• Grey snow mould (Typhula blight)Typhula incarnata

  Circular bleached, straw-grey to silvery patches up to about 30 cm across that appear as snow melts in late winter and early spring. Leaves within the patch are matted and water-soaked, often with a greyish-white fungal felt; the diagnostic clue is tiny hard reddish-brown to dark resting bodies (sclerotia, pinhead-sized) embedded in the dead leaves and crowns. Damage is usually to the foliage only, so affected lawns commonly recover as growth resumes.

• Fairy ringMarasmius oreades

  Arcs or complete rings, from under a metre to many metres across, of dark-green, fast-growing grass, often with a band of dead or thinned turf just inside, and small tan mushrooms appearing after rain. In dry weather the ring zone becomes hydrophobic (water-repellent) so the grass there wilts and browns even when surrounding turf is green; a mushroom smell and white fungal threads are found in the thatch and soil.