Dr. Phyto

zoysia grass

Zoysia japonica

Diseases & pests on this plant

• sheath blightRhizoctonia solani
• Thatch accumulation (lawn)Lawn thatch accumulation

  The lawn feels soft, spongy and bouncy underfoot, and a thick brown layer of dead stems and roots can be seen between the green leaves and the soil when you part the grass. The turf dries out quickly, water runs off or sits on top, and the grass becomes thin, pale and prone to scalping and disease.

• 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.

• Soil compaction (lawn)Lawn soil compaction

  Grass grows thin, weak and pale along paths, gateways, play areas and other heavily walked routes, with hard ground that is difficult to push a fork into. Water puddles on the surface after rain instead of soaking in, and moss and weeds often move into the worn lines.

• 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.

• Brown ring patch (Waitea patch)Waitea circinata var. circinata

  Yellow to bronze rings and arcs from a few centimetres up to 60 cm across, mainly on annual meadow-grass (Poa annua), that can look like a smaller, yellower version of brown patch. Rings often turn tan and slightly sunken; in cool, wet spring weather a thin web of mycelium may be visible in early morning. Roots and crowns can be discoloured but the disease is usually foliar and recovers with growth, so it is mostly a problem on fine sports turf rather than home lawns.

• 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.

• Nitrogen deficiency (lawn)Lawn nitrogen deficiency

  The whole lawn fades to a uniform pale green or yellow, oldest leaves first, and grows slowly with little need for mowing. The turf looks thin and lacklustre, clover and weeds (which fix their own nitrogen) often stand out greener than the grass around them.

• 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.

• Spring dead spot (Bermuda grass)Ophiosphaerella herpotricha

  Circular, sunken, straw-coloured to bleached dead patches 10 cm to over 1 m wide that appear exactly as the Bermuda grass greens up in spring. The turf stays dead inside the rings long after the rest has recovered; living grass at the edges may re-colonise from the centre, giving a doughnut shape. Pulling up affected runners shows blackened, rotten, brittle roots and rhizomes.

• 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.

• 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.