Ophiosphorella (formally Leptosphaeria) herpotricha, O. korrae, and O. narmari.

What is Spring Dead Spot?

Spring Dead Spot (SDS) is one of the most significant diseases affecting couch (Cynodon spp.) and hybrid bermudagrass turf. Caused by Ophiosphaerella fungi, the disease infects roots, rhizomes, and crowns during autumn and winter, weakening the plant before dormancy.

While infection occurs during the cooler months, symptoms don’t typically appear until spring when healthy turf begins to green up and infected plants fail to recover.

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Symptoms of Spring Dead Spot

Above-Ground Symptoms

• Circular patches of straw-coloured or dead turf.
• Delayed spring green-up compared to surrounding areas.
• Patches ranging from 10 cm to over 1 metre in diameter.
• Weed invasion, particularly winter grass (Poa annua).
• Patches often reappear in the same locations each year.

Below-Ground Symptoms

• Darkened or rotting crowns and rhizomes.
• Reduced root mass.
• Weak underground plant tissue.
• Slow recovery during the growing season.

As the disease progresses, patches may enlarge and merge, creating larger areas of turf loss.

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Conditions That Favour Disease

Several factors can increase the severity of Spring Dead Spot:

• Excessive nitrogen applications late in autumn.
• High soil pH.
• Poor drainage and waterlogged soils.
• Soil compaction.
• Thatch accumulation.
• Drought, wear, or other environmental stresses.

Disease infection generally begins during autumn as soil temperatures decline, making preventative management critical.

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Management Strategies

Improve Turf Health

Healthy turf is more capable of tolerating infection and recovering from damage.

Key cultural practices include:

• Aerating to relieve compaction.
• Improving drainage.
• Managing thatch levels.
• Maintaining balanced nutrition.
• Encouraging strong root and rhizome development during summer and autumn.
• Avoiding excessive late-season nitrogen applications.

Maintaining adequate potassium levels can also help improve stress tolerance heading into winter.

Fungicide Control

Fungicides are most effective when applied preventatively during autumn, before infection becomes established.

Because Spring Dead Spot is a root and crown disease:

• Applications should be watered into the rootzone.
• Timing is more important than curative activity.
• Sites with a history of disease may benefit from multiple autumn applications.

Once symptoms appear in spring, fungicides provide limited benefit and recovery efforts should focus on promoting healthy turf growth.

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Recovery

Recovery can be slow depending on the severity of crown and rhizome damage. Practices such as aeration, balanced fertility, moisture management, and encouraging stolon growth can help affected areas fill in during the growing season.

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Key Takeaway

Spring Dead Spot is a preventative disease rather than a curative one. Infection occurs during autumn, but symptoms appear during spring green-up. The most effective control strategy combines strong autumn turf health, sound soil management, and well-timed fungicide applications to protect roots, rhizomes, and crowns before damage occurs.

See more on SDS from our friends at Syngenta – https://www.syngentaturf.com.au/disease-roots/spring-dead-spot

The experts at Lawn Addicts can help with lawn care programs for Spring Dead Spot, based on grass identification.