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For those Tumbleweed lovers in Australia, many have faced escalating heat waves in the summer of 2025/26, causing all sorts of problems, including anyone who is running a worm farm at home. Not only were some parts of Australia experiencing their highest ever maximum temperatures approaching 50 degrees C, there was little time for recovery as rolling heat waves meant day after day of temperatures in the 40’s. Similar heatwaves have been felt in other parts of the world due to climate change and global heating. Whilst worm farms are remarkably efficient composting systems, summer heat can quickly turn a thriving worm farm into a smelly, pest-ridden problem if conditions slip out of balance, with the worst-case scenario being the loss of our wriggly composting buddies to overheating. As well, high temperatures accelerate decomposition, increase moisture loss, and encourage pests—making summer the most challenging season for worm farmers. Understanding the causes of common problems and responding early will keep your worms healthy and productive through the hottest months.

Odours: What Smells Mean and How to Fix Them

A healthy worm farm should smell earthy, like forest soil. Strong or unpleasant odours are almost always a sign of anaerobic conditions—too much moisture, compacted bedding, or excess food breaking down without enough oxygen. In summer, odours often develop because food decomposes faster than worms can consume it. Overfeeding is the most common cause, particularly over the holiday season, when there is usually an abundance of kitchen scraps and left over food.

How to fix it:

• Stop feeding until your worms catch up. You will know because there is a teeming mass of worms built up below the last lot of food added. Excess scraps can be buried in the garden.
• Gently fluff and loosen bedding to improve airflow with a Worm Farm Aerator | Tumbleweed or similar tool.
• Add dry, carbon-rich materials such as shredded cardboard, egg cartons, or newspaper to saturated areas.
• Bury food scraps lightly and cover with a Worm Blanket - Rectangle | Tumbleweed, Worm Blanket - Round | Tumbleweed, damp newspaper, or hessian.

If the smell persists, remove any slimy or rotting food and bury it in the garden, and check that excess liquid can drain freely from the system.

Pests: Ants, Flies, and Other Unwanted Visitors

Summer heat brings pests, and worm farms are no exception. Ants, vinegar flies, soldier fly larvae, and cockroaches are the most common intruders.

Ants are attracted to dry conditions and sugary food. Their presence usually means the farm is too dry.

• Increase moisture slightly.
• Stand the legs of the worm farm in containers of water or apply a petroleum jelly barrier.
• Avoid sweet foods near the surface.

Vinegar flies appear when food scraps are exposed.

• Always bury food under bedding.
• Freeze scraps before adding them to kill fly eggs.
• Cover the surface with a worm blanket, damp newspaper, or hessian.

Soldier fly larvae thrive in very warm, wet, food-rich environments. While not harmful, they compete with worms.

• Reduce feeding.
• Remove excess larvae and add them to the garden or lawn where birds will feast on them.
• Add dry, carbon-rich bedding to rebalance moisture.

Moisture Management: The Summer Balancing Act

Moisture is usually the most important factor in summer worm farm management. Worms breathe through their skin and require moisture—but too much creates anaerobic conditions, while too little leads to dehydration and escape attempts.

The ideal moisture level is often compared to a wrung-out sponge. A pH Tester | Tumbleweed can also measure moisture without getting your hands dirty.

Too wet?

• Pools of liquid forming
• Sour or rotten egg smells
• Worms trying to escape

Solutions:

• Check drainage holes and taps for blockages.
• Add dry, carbon-rich materials.
• Reduce watery foods such as melon and tomatoes.
• Ensure the farm is well shaded and ventilated.

Too dry?

• Ant infestations
• Inactive or deeply clustered worms
• Dusty bedding

Solutions:

• Lightly mist bedding with rainwater.
• Add moist cardboard or coconut coir.
• Increase shade and insulation.

Heat Stress: The Hidden Summer Threat

Compost worms perform best between 15–25 °C and become stressed above 30 °C.

Prevent heat stress by:

• Keeping worm farms in full shade.
• Elevating bins off hot concrete or brick.
• Increasing airflow without drying bedding.
• Freezing food scraps before adding them.
• Using frozen water bottles and light-coloured coverings for evaporative cooling.

A Summer Maintenance Mindset

Summer worm farming is about observation and adjustments when heat waves are forecast. Check your worm farm every few days during hot weather. If something smells wrong, looks wrong, or behaves differently—it usually is.

By providing cooling measures in heat waves, managing odours early, discouraging pests through good feeding habits, and carefully balancing moisture, your worm farm can remain productive all summer long. With a little attention, worms will reward you with rich castings and liquid fertiliser just when your garden needs them most through the growing season. 

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