Summer Worm Farm Care (Australia): Keeping Worms Alive in Heatwaves

Why worm farms struggle in Australian summers

We love summer for its long evenings, tomatoes, chillies and mangoes. Our compost worms, on the other hand, are much less impressed. Most compost worm species used in home vermicomposting prefer a fairly narrow temperature range and can suffer from heat stress long before we notice a problem.

A typical worm farm in summer can heat up quickly if it is in direct sun, sitting on hot concrete or not protected from hot winds. Once temperatures spike inside the farm, the bedding can dry out, food can go sour, and worms may try to escape or, in worst cases, die off.

At Maze, we design our worm farm range to support healthy airflow, drainage and easy management. With a few smart summer tweaks, your worms can keep turning food scraps into beautiful castings, even during a heatwave.

Ideal worm farm temperature

For most compost worms, the ideal worm farm temperature is generally around room temperature. Broadly speaking:

• Comfortable: roughly 15–25 °C
• Manageable but stressful if prolonged: around 26–30 °C
• Risk zone: once bedding starts creeping above the low 30s °C, especially in a closed plastic system

This is why positioning and daily care are so important in Australian conditions. The Maze Worm Farm, for example, has ventilated trays and a liquid collection tray, which help with airflow and moisture control, but you still need to manage exposure to direct sun and reflected heat.

Step 1: Smart placement for summer – shade and airflow

The single biggest factor in keeping worms cool is where you put the farm.

Choose shade over sun

• Place your farm in a shaded spot that avoids direct midday and afternoon sun.
• Ideal locations include under a pergola, veranda, carport, shaded side of the house or beneath a deciduous tree that lets winter sun in and blocks harsh summer rays.
• Avoid open concrete or pavers that radiate heat back up into the base of the farm. If concrete is your only option, sit the farm on a wooden pallet, piece of timber or thick rubber mat to insulate it.

Prioritise airflow

Shade and airflow work together. A worm farm hidden in a cramped, airless corner can still overheat. Try to:

• Leave a bit of space around the farm so breezes can move past it.
• Avoid surrounding it completely with solid walls or large objects.
• Keep the lid on, but check that ventilation holes are clear and the drainage system is not blocked.

If you have one of our Maze Worm Farms with legs, that elevated design helps air circulate under and around the unit, which is especially useful in summer.

Step 2: Moisture management in hot weather

Moisture is your worms’ air conditioner. Correct moisture management keeps bedding cooler and much more comfortable.

The right moisture level

Inside the working tray, bedding should feel like a wrung out sponge:

• Too dry: bedding feels crunchy, light or dusty. Worms will huddle deep down or along the sides seeking moisture.
• Too wet: bedding turns sloppy, smells sour and may go anaerobic, which is dangerous in hot conditions.

In summer you may need to:

• Lightly sprinkle water on the surface every day or two, particularly during a heatwave.
• Keep a moist, breathable cover over the top bedding layer, such as a piece of damp cardboard, hessian, or a Maze style worm blanket. This helps hold in moisture while still allowing air to move.
• Check the liquid collection tray more often and empty any leachate so it does not stagnate.

Never pour large amounts of icy cold water straight in during a hot spell. Rapid temperature shocks are as stressful for worms as steady overheating.

Step 3: Cooling tricks for heatwaves

When the forecast is predicting several days in the mid to high 30s or more, it is time to move from general worm farm summer care into active cooling mode.

The frozen water bottle trick

The frozen water bottle trick is one of the simplest, safest ways to bring the temperature down:

1. Fill a plastic bottle with water and freeze it.
2. Wrap it in a thin cloth or tea towel so it does not stick to bedding.
3. Lay it on top of the bedding under the farm’s lid, but not pressed hard into the main worm mass.

Worms will move closer if they want the cooler area and retreat if it is too chilly. Use two bottles in rotation on extremely hot days, swapping them morning and evening.

Extra shading and insulation

On extreme days, also consider:

• Draping an old cotton sheet over and around the farm (but not blocking ventilation holes) to provide extra shade.
• Moving the farm temporarily into a garage, laundry or undercover area that stays cooler than outside.
• Avoiding any agitation that would bring hot outer layers into the cooler centre of the bedding during the hottest part of the day. Turnings or tray changes are better done early morning or evening.

Step 4: Adjusting feeding during very hot weather

Your worms will slow down in the heat, and your feeding should slow down too.

Should you feed less?

Yes. During heatwaves it is wise to feed less and focus on easier, safer foods. This helps in several ways:

• Less risk of rotting, smelly food heating up inside the farm.
• Reduced chance of attracting pests if worms cannot keep up.
• Lower overall biological heat production from rapid decomposition.

If you notice uneaten food sitting there for more than a couple of days, stop adding more until the worms have caught up.

Safer foods for hot weather

Better choices in very hot conditions include:

• Soft fruits and veg cut into small pieces (avoiding large piles)
• Coffee grounds and tea leaves (used lightly, mixed into bedding)
• Shredded, damp cardboard and paper to help balance moisture

Foods to go easy on in a heatwave:

• Big loads of citrus, onion or spicy leftovers
• Meat and dairy (if you usually add them)
• Large wet piles of one food type, like a whole watermelon rind heap

Spread each feeding thinly across the surface rather than burying big clumps. This reduces hot spots and helps air flow around the food.

Signs of heat stress in worms

Catching trouble early is key to keeping worms cool and alive. Watch for:

• Worms clustering at the very top of the tray or trying to escape under the lid
• Worms bunched around drainage holes at the base
• Bedding looking dry on top and pulling away from the sides
• Strong odour or patches of slimy, cooked looking worms

If you see these signs:

1. Move the farm to the coolest possible spot straight away.
2. Use the frozen bottle method and add a fresh damp cover.
3. Gently add a small amount of cool, not icy, water if bedding is dry.

With quick action, many worm farms can recover from moderate heat stress.

Using Maze worm farms for summer success

Our Maze Worm Farm range is designed with Australian conditions in mind. Features that help in summer include:

• Stackable trays that allow worms to move up and down, seeking their preferred temperature zone.
• Ventilated lids and sides that encourage airflow while keeping light out.
• Leachate collection to stop the lower section from becoming waterlogged and overheated.
• Optional wooden legs or stands that lift the farm off hot surfaces, improving circulation.

Paired with sensible placement, moisture care and occasional cooling tricks, these design features help worms stay active and productive even when the weather turns fierce.

FAQs

What temperature is too hot for compost worms?

Compost worms start to feel stressed once bedding climbs into the high 20s °C, and the risk rises quickly past the low 30s °C. There is no single exact cut off, because materials, airflow and moisture all play a role, but if your worm farm is in full sun on a 35+ °C day, conditions inside can become dangerous. In Australian summers, we treat anything above the high 20s °C as a prompt to check placement, moisture and shading and to prepare cooling strategies for upcoming heatwaves.

How can I cool a worm farm down during a heatwave?

To cool a worm farm in summer you can:

• Move it into deeper shade or a sheltered area such as a veranda, pergola or cool garage.
• Lift it off hot concrete using timber or a stand.
• Keep bedding moist with a damp cover like hessian or cardboard.
• Use the frozen water bottle trick on top of the bedding under the lid.
• Reduce feeding temporarily so food does not rot and add extra heat.

Combined with the airflow and drainage features in our Maze worm farms, these simple actions can make a big difference to worm survival.

Should I feed less during very hot weather (and what foods are safest)?

Yes, you should generally feed less during heatwaves. Worms slow down in high temperatures, so overfeeding can lead to smelly, decomposing food that heats up the system and attracts pests. In extreme heat, offer smaller amounts more spread out, focusing on chopped fruit and veg, coffee grounds and damp shredded paper or cardboard. Avoid very oily, heavy or large single type loads and pause feeding entirely if there is still a lot of uneaten food sitting in the tray.

resilient worms for hot Australian summers

With a little planning and care, your worms can be as resilient as the rest of your garden in summer. By focusing on shade, good airflow, steady moisture and a few cooling tricks during heatwaves, your worm farm summer care routine can keep compost worms thriving rather than just surviving.

At Maze, we design our worm farms to work with Australian conditions and to make vermicomposting in summer simple and practical. With the right setup and habits, every heatwave becomes just another season your worms help you turn kitchen scraps into rich, living soil.