Lesson 4 - Part A: WORM FARMS
Lesson 4 – Part B: COLLECTING WORM CASTINGS
The worms that live in worm farms are 
different from the earthworms that you
may see in your compost factory and
your garden, even though worm-farm
worms are often called 'compost worms'.
Worm farm worms do not make tunnels
in soil and will die in the garden if the
soil becomes dry. They love eating soft
organic waste. When they have finished
eating the waste, it becomes a dark brown, soft material called 'worm
castings'.
Worm-farm worms like wetter conditions than earthworms, but they need a home where water can drain away so that they do not drown.
Your school may have bought a plastic worm farm or parents may have made a special home for your worm farm at school. Both types of farms need the same things. Most important is to give your worms a shady spot where the temperature won't get higher than 30° Celsius. Worm-farm worms will die in very hot or very cold temperatures, and they work fastest when the air temperature is about 24° Celsius.
If you haven't poured water through fresh organic waste in the farm, the liquid that drains from raised worm farms can be watered down and used as a liquid plant food. (If the water runs through the castings, it is ok to use because they are a form of compost but, if it has been poured through foods scraps it can contain nasty pathogens.) Another way to make liquid plant food from worm farms is to take some of the worm castings and dissolve them in water until the water is the colour of weak black tea. Very weak 'Worm tea' is the best plant food for seedlings because it is gentle to delicate new leaves and roots and it contains everything they need to grow strong.
Worm farms need soft bedding for the worms to live in before they make worm castings. Coconut fibre that has been finely shredded and soaked in water makes good beds for worm-farm worms. Worms like to work where it is dark and damp so, after you add some food for them, cover the food with a few sheets of wet newspaper or wet hessian potato sacks before replacing the cover on the farm. If your worm farm is new, don't give them too much food at first or it will be a while before they eat all the food and the coconut fibre, and it will start to smell. But, if you don't give your worms enough to eat, they will eat the paper and potato sacks, too!
Worms have very tiny mouths and they change the food into castings by nibbling around the edges of the food. If you chop or tear the food into small pieces before putting it in the worm farm, the worms can eat faster, grow bigger, and lay eggs, so that you will have lots more worms very soon.
Worm-farm worms are very good at looking after themselves during school holidays. If you leave them a good supply of food, and make sure they are protected from drowning, they will munch away happily until school starts again.
Did you know that worms are very good at telling when it is going to rain? If you see your worms crowding around near the top of your worm farm, you will know that it is time to put a water-proof cover over the farm because heavy rain is on its way.
FOOD FOR WORM FARMS
- Fruit and vegetable scraps and peels (chopped or torn into small pieces)
- Used tea bags and coffee grounds
- Torn up paper and cardboard cartons that have been soaked in water
- Vacuum cleaner contents and hair
- Small amounts of soft weeds and grass clippings
Worm-farm worms don't like onions or citrus and will try to avoid eating them
Instead of spreading the food across the top of the worm farm, put it at one end. When worms have eaten that food, start feeding them at the other end of the farm. This will make it easier for you to collect worm castings without having to move their food.
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COLLECTING WORM CASTINGS
From homemade worm farms:
To collect worm castings to use on your
garden, first uncover the worm farm and
wait for about 10 minutes. The worms will
move down into the castings away from
the light.
Use a scoop to collect a layer of castings
from the top of the farm. Check for any
small worms that might still be in the
castings and put them safely back into
the farm. Then tip the worm castings into a bucket and collect another scoop full of castings until you have enough to put into your garden bed, or to make 'worm tea'.
If your farm is new, and you want to increase
the number of worms in your farm, you will have to remove any worm eggs from the castings and put them up the other end of the farm.
To find the eggs, tip the scoop full of castings onto an old tray and brush it gently into a thin layer with the palms of your gloved hands.
Pick up the worm eggs using an old spoon and put them near the fresh food at the other end of the farm. You can see from the photo what worm-farm eggs look like. They are about the size of the head of a match, or a little bit smaller. Worms don't lay their eggs in groups like some insects do. They lay them one at a time through the worm castings, but usually close to where they can find food when they hatch.
From worm farm trays:
Worms in farms with stacked trays will move up into the next highest layer when all the food in their tray has been eaten, and it is time to collect the worm castings.
You will still have to look for eggs in the castings and put them in the tray where there is food if you want more worms in your farm.
Don't forget to replace the cover on your worm farm after adding food or collecting castings!
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