Summer Lawn Diseases to Watch For in Sydney: How to Protect Your Yard from Brown Patch, Dollar Spot & Leaf Spot
Summer Lawn Diseases to Watch For in Sydney: How to Protect Your Yard from Brown Patch, Dollar Spot & Leaf Spot
Summer in Sydney rolls in like a warm, golden tide long days, bright skies, and gardens glowing under the sun. But for lawns across the Inner West, this season also opens the door to a less welcome guest: summer lawn fungus. When humidity climbs, nights stay warm and storms sprinkle the perfect amount of moisture, fungal diseases flourish.
If you’ve noticed brown patches, greyish circles, or dark, water-soaked spots creeping through your lawn, you’re not alone. Homeowners across Sydney face a surge of turf diseases every summer especially those living in leafy, moisture-rich suburbs like Newtown, Lilyfield, Ashfield, Leichhardt, Five Dock, and Marrickville.
To help you stay one step ahead, here’s your complete guide to summer lawn diseases to watch for, what they look like, why they show up, and how a professional service like Bizzy Mowing can help your lawn bounce back stronger than ever.
Why Summer Fungus Is So Common in Sydney
Sydney’s summer climate is a fungal playground.
Warm days + humid nights + irregular rainfall
= perfect breeding conditions for turf diseases.
Even the healthiest lawns can fall victim when moisture becomes trapped between tightly packed grass blades or when soil stays damp for too long.
Some of the biggest risk factors include:
Overwatering or watering at night
Poor airflow or heavy shade
Compacted soil
Thick thatch layers
Using too much nitrogen fertiliser in summer
Mowing the lawn too short
Stressed or weakened grass
Understanding these triggers helps you prevent many common lawn diseases before they spiral into landscaping headaches.
Brown Patch
Brown Patch is the heavyweight champion of summer lawn diseases in Sydney. It thrives in humidity, appearing overnight like a burnt-orange halo stamped onto your grass.
What It Looks Like
Brown Patch forms:
Circular or ring-shaped brown areas
Patches ranging from 20cm to several metres wide
Edges that appear smoke-coloured in the early morning
Leaves that rot at the base when humidity is high
If your lawn looks like it has been branded by a giant, ghostly doughnut, you’re likely dealing with Brown Patch.
What Causes It
Night watering
Long periods of humidity
Over-fertilising during summer
Poor airflow or shaded areas
Wet grass overnight
How to Treat Brown Patch
Improve airflow by pruning back dense plants
Water early in the morning (never at night)
Avoid high-nitrogen fertilisers in summer
Mow regularly & keep blades sharp
Apply a fungicide if patches continue to spread
For persistent cases across the Inner West, Bizzy Mowing offers tailored treatments and lawn recovery services designed for Sydney’s climate.
Dollar Spot
Dollar Spot is small but mighty. Each individual spot is about the size of a ten-cent coin—hence the name but it spreads like wildfire.
What It Looks Like
Straw-coloured, sunken patches
Spots that merge into larger, bleached areas
Short lesions with reddish-brown borders on individual blades
A cobweb-like fungus visible in the early morning dew
It especially loves Kikuyu, Couch, and Buffalo, which are common across Sydney.
What Causes It
Dollar Spot thrives when:
Soil nitrogen is low
Mowing is inconsistent
Lawns stay wet for long periods
There is thick thatch buildup
Sydney’s dry-spell-followed-by-storm pattern is textbook perfect for this disease.
How to Treat Dollar Spot
Fertilise with a balanced, slow-release formula
Water deeply but infrequently
Remove thatch every 1–2 years
Apply a preventative fungicide during humid months
If your lawn is riddled with tiny bleached spots and you’re unsure how to fix them, Bizzy Mowing can diagnose and treat Dollar Spot with precision.
Leaf Spot
Leaf Spot is one of the sneakiest summer lawn diseases. Instead of immediately damaging turf, it starts small dark, water-soaked lesions that slowly widen and dry out.
What It Looks Like
Purple, dark brown or black spots on blades
Blades thinning over time
Patches of straw-coloured grass
Melting out where blades die back from the tip
Leaf Spot can turn a lush lawn into a brittle patchwork if ignored.
What Causes It
High humidity (especially after storms)
Shade + poor airflow
Too much thatch
Overwatering
Dull mower blades that tear grass
It often affects lawns weakened by heat stress common during Sydney’s intense summers.
How to Treat Leaf Spot
Reduce watering to the morning only
Aerate to improve airflow & drainage
Sharpen mower blades
Apply a broad-spectrum fungicide if needed
For ongoing Leaf Spot problems, Bizzy Mowing can create a maintenance plan to protect your turf for the entire season.
Other Summer Lawn Diseases Sydney Homeowners Should Watch For
Even though Brown Patch, Dollar Spot, and Leaf Spot are the big three, several other diseases can strike Sydney lawns during summer:
Helminthosporium
Creates blackened streaks and thinning areas.
Pythium Blight
Looks like greasy, collapsed grass a fast-moving nightmare in humid weather.
Rust Fungus
Dusty orange powder on blades, common in shaded or poorly nourished lawns.
Fusarium Patch
Often mistaken for drought stress but has a distinctive bleached look.
Being able to identify these conditions early can save you hundreds in lawn restoration costs.
How to Know If You Have Summer Lawn Fungus
If you’re unsure whether your lawn is battling fungus or just heat stress, here are signs that point to fungal disease:
Circles or rings form in the lawn
Patches grow rapidly over days
Discoloured blades have defined edges
A cotton-like web appears in the morning
Grass feels slimy or looks wet despite dry weather
Patches stay even after watering
When in doubt, a lawn professional can diagnose the issue quickly saving time, money, and turf.
Prevention: The Best Defence Against Summer Lawn Fungus
The secret to fungus-free summers in Sydney is a proactive, consistent care routine. Here’s how to build one.
Water Wisely
Overwatering is the number one cause of summer fungus.
Water:
Early mornings only
Deeply but less often
Avoid getting foliage wet
Using a timer or irrigation system helps keep watering consistent.
Mow at the Right Height
Scalping the lawn weakens roots and invites disease.
Keep Buffalo between 40–60mm
Keep Kikuyu at 30–50mm
Keep Couch at 20–30mm
Bizzy Mowing uses sharp blades and correct mowing heights to keep lawns healthy without stress.
Improve Drainage & Airflow
Fungi thrive in still, damp environments.
Aerate compacted areas
Dethatch when buildup forms
Trim overhanging branches
Improve sun exposure where possible
Fertilise the Right Way
Avoid heavy nitrogen in summer it overfeeds soft growth that fungi love to attack.
Choose:
slow-release
balanced
warm-season-friendly fertilisers
Bizzy Mowing provides seasonal fertilising tailored for Inner West conditions.
5. Use Preventative Fungicide if Needed
Some lawns especially shaded, moist, or older ones benefit from a preventative fungicide plan.
This is common in suburbs like Summer Hill, Petersham, and Balmain where leafy canopies keep lawns wet longer.
How Bizzy Mowing Helps Inner West Sydney Lawns Stay Healthy in Summer
When fungus strikes, timing is everything. Bizzy Mowing steps in like a summer lawn guardian, offering services that stop fungal diseases before they take over:
Professional lawn disease diagnosis
Targeted fungus treatments
Seasonal mowing schedules
Aeration & dethatching
Fertilising tailored to Sydney summers
Lawn recovery & patch repair
Ongoing maintenance programs
Our team knows Sydney lawns inside and out from Balmain’s shady garden pockets to the sun-baked yards of Ashfield and Haberfield.
When your lawn starts whispering its worries through strange circles and discoloured blades, we’re here to interpret the signs and restore the green.
A Healthy Lawn All Summer Long Starts with Early Action
Summer should be a season of barefoot strolls, backyard barbecues and grass that feels like a soft welcome mat. But when brown patch, dollar spot, or leaf spot show up, the dream can quickly fade.
By learning what these diseases look like, understanding why they occur, and taking preventative steps early, you can keep your lawn lush and resilient even through the hottest Sydney days.
And if fungus has already moved in?
Bizzy Mowing is ready to send it packing.
For expert lawn care, fungus treatment and summer-proof lawn maintenance across Inner West Sydney, you can count on us to keep your garden fresh, vibrant and beautifully green.
