Dr. Phyto

Tall fescue

Schedonorus arundinaceus

Diseases & pests on this plant

• sheath blightRhizoctonia solani
• rice blastMagnaporthe oryzae
• Leaf spot and common root rotBipolaris sorokiniana

  Small dark brown to black leaf spots, often with a yellow halo, that enlarge and merge to blight whole leaves in warm, humid weather; on close-mown turf this becomes a general thinning and bronzing. Below ground the same fungus causes a brown rot of roots, crowns and stem bases, so plants are easily pulled up and the turf melts out in diffuse, irregular brown areas. Most damaging in warm summer spells on stressed, thatchy lawns.

• 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.

• 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.

• 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.

• Pythium root rotPythium aphanidermatum

  Yellowing + wilting leaves despite wet soil (the diagnostic combination), brown mushy roots when plant is unpotted, foul earthy smell from rotting roots, plant easily pulled from pot with most root system left behind in mix, stem base softening + black at soil line in severe cases.

• 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.

• crown rust of oatPuccinia coronata

  Bright orange-yellow pustules on leaves with characteristic crown-shaped teliospores in late season, severe infection causes premature leaf death + lodging, kernels do not fill properly leading to shrivelled grain, in epidemic years 50%+ yield loss with poor grain quality.

• Scalping injury (lawn)Lawn scalping injury

  Pale brown, almost bald strips and patches appear immediately after mowing, exposing stems and bare soil where the mower cut into high spots, bumps or slopes. The damage follows the contours of the ground and the mowing pattern, and often shows brown crowns and stubble rather than green leaf.