Worms cannot stand temperatures above 95 degrees Fahrenheit (35 degrees Celsius) in worm farms or bins without some help. Keeping them cool can be simple and is essential in hot climates. To keep worms cool in hot climates, place them in a position that gets all day shade, use a moist worm blanket, add frozen food scraps and wash the farm through with water.
This article will explore 8 easy ways to keep composting worms cool in hot climates that is easy to do at home, takes no special equipment and will keep your worms safe.
I have been keeping worms for over 15 years and these tips have helped me to keep worms happy and healthy in temperatures even above 104°F (40°C)
Top 8 ways to keep worm farms cool in hot climates
1. Place them in full shade
The most important thing to consider in hot climates is to place worm bins in a position that gets full shade all day. In hot climates, even the morning sun can heat up the black plastic of worm bins.
Find a position against a wall, under a tree or under a verandah that protects the whole worm bin from sun. Afternoon sun in particular will heat up worm bins quickly and kill worms.
My worm bin is currently next to a garden screen and garden wall giving it full shade each day. My Styrofoam worm farm is in the corner of my yard between my garden wall and raised garden beds. My banana tree also provides it with shade which has kept it happy over long summers.
2. Use shadecloth
Shadcloth is a handy material to provide worm bins with shade. You can bang in some stakes around the worm bin and gently drape shadecloth over the top. 50-80% shade cloth works well to provide worms with extra shade.
Shadcloth can be taken off, folded up and stored over the fall and winter when the weather cools. This solution is great for a temporary summer shade to keep the worms safe.
3. Moisten a worm blanket
All worm farms work best if they are covered with a worm blanket. One that is made from natural materials like coconut coir, hessian, cotton or jute all work well. My worm blanket is currently made from an old coffee bean bag. This was salvaged from a coffee bean roastery and cut into pieces.
Soak the worm blanket in a bucket of water until it has been soaked through. You may need to repeat this a few times over a hot day to keep the worm farm cool. Worm blankets can dry out quickly if the temperature is above 100 degrees F.
You can even cover the worm farm with a free worm blanket made from cardboard or newspaper. Use thick cardboard soaked for 5 minutes in water or 5-7 pieces of newspaper that have been dunked. Both of these will help to keep the worm farm moist and cool in hot weather.
4. Freeze some food scraps
A great way to feed worms and cool the worm farm is to add frozen food scraps. Put your food scraps in an old ice cream container and just cover them with water. Freeze this overnight and pop the whole lot in the worm farm. This will cool the worm farm and feed the worms.
When the temperature is very hot, worms will usually head deeper under ground to hide out until the weather cools. After that they will venture back up to the surface to eat the food.
Adding frozen food scraps is a great way to lower the temperature of your worm farm and to make sure they have some food scraps ready to eat when the weather cools.
5. Add ice
Adding ice to your worm farm is a simple way to keep it cool in hot weather. You can half fill ice cream containers for a larger block of ice or add ice cubes. I find that a larger piece of ice works best because it will take longer to melt.
Small ice cubes can be scattered over the top of the worm farm to gently cool the bin. Remember to have the drainage tap open on the bottom to let any excess water drain through.
6. Wash through with cool water
Another way to cool worm farms on hot days it to wash it through with cool water. Run your hose until cool water comes through and add around 1 gallon of water to a bucket. Wash through the worm farm with around a gallon of water to start with (4-5 Liters).
Pour all of the water over the surface of the worm farm gently. This will help to cool the worm farm. Open the tap at the bottom of the worm farm. Let the water drain through into a bucket or onto the ground.
The water can be captured and placed in your compost or on large trees if it doesn’t smell.
7. Use Styrofoam
Styrofoam worm farms are fantastic in hot climates. They keep the worms and the worm bin contents cool for longer. Styrofoam is a great insulator. I like to keep my Styrofoam worm farm in the shade, covering it with banana leaves, a worm blanket and washing it through with water on very hot days.
My Styrofoam worm farm has actually kept cool and the worms safe all over summer just by keeping it in the shade.
8. Use deep worm farms
For very hot climates, deep worm farms will help to keep worms cool. Baths tubs, worm farms made from natural materials like timber are all great ways to make deep worm farms. Bath tubs can be dug into the soil half way to help to keep worms cool.
The deeper the worm farm is, the cooler it will stay. It is still best to keep these worm farms in full shade to keep them moist. Worms will dig down deeper when the weather warms up and will dig their way back up when it cools again in the evening.
Feed worms small amounts of food scraps at the end of the day to keep them happy.
Worm Composting in Hot Climates | Summary
Worm composting is easy in hot climates if you know a few tips to keep your worms cool. Using free or cheap materials like shadecloth, soaked cardboard, newspaper and shade trees to keep them cool. Washing worms through with cool water is a great way to cool the temperature of your worms.
Worms are easy to care for and are very rewarding. They will consume and digest your food scraps turning them into garden gold called worm casting which can be added to your garden before planting.
Worms need a little bit of care in the hot weather but it is worth it to keep them alive and happy.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.