G3 Worm Farming

August 29, 2013

We gathered at Katie C’s place in Te Puna this morning for the much-anticipated worm talk.

Bruce Trask and Kim Edwards from Tauranga-based Waste Education NZ brought along our vermihuts and laid them along the driveway.
Each pack contained:
   1000 worms
   Some lovely compost
   Lime
   The multi-tiered hut
   An instruction booklet

Bruce has been a zero-waste educator since 1993. He’s pretty-much retired now; Kim and other colleagues have taken on the job of educating kids in schools, and running large community seminars as well as wee workshops like ours. They take zero-waste education into about 500 schools (years 1-8) in 19 jurisdictions nationwide. Tauranga City Council subsidises the local programme, so our vermihuts and instruction only cost $30 each.

Why farm worms?

In April of this year, Tauranga City Council did a particularly gross survey: for one week, they sifted through 1000 rubbish bags collected from the curb to assess what waste is heading to landfill.

It broke down like this:
2% metal
4% glass
2% plastic
11% paper
30% kitchen scraps
16% green waste
7% nappies and other sanitary items
28% other

The point of worm farming is to reduce that 30% of kitchen scraps which, if sent to landfill, contributes to greenhouse gas.

Kim said the Ministry for the Environment calculated that, in one month, New Zealand households accumulated enough rubbish to fill a rugby field - and rise 30 stories high. That’s three times the height of Mt Maunganui’s twin beachfront apartment blocks.

Worms

There are 1800 different types of worms. The worm farms use tiger worms because they are the most efficient at processing waste. They won’t survive in your garden – but they’ll do a great job of producing valuable vermicast which you can dig in to your soil!

The tiger worms live for around eight years. They will each breed about 30 babies every six weeks. The saddle is where the eggs are made (the lump closer to their heads). They get oxygen and water through their skin, use hairs like little hooks to wade through the soil, and have up to 10 hearts. The worm, a non-arthropod invertebrate animal, is a hermaphrodite.

It’s important worms don’t get too hot, or too cold (although it’s frozen soil they dislike so the Tauranga winter should be fine). For this reason, it may be a good idea to keep your worm hut in at least partial shade. If the conditions aren’t right, the worms won’t breed.

Feeding your animals

The optimum diet for a worm farm is 60 percent nitrogen and 40 percent carbon. 
Nitrogen foods are wet. Examples include fruit and veg peelings and leafy vegetables. 
Carbon foods are dry and examples include paper, cardboard, dead leaves, teabags, coffee grinds.

If you accidentally put in a sticker on your banana peel, the worms will eat around it. They are very adept at spotting non-plant material and avoiding it.

Go easy on the oranges and lemons, and avoid all animal products such as eggs, butter and meat, all oils and onion peels, and cooked foods such as bread.

Setting up your farm

Now for the exciting bit! The bottom tray needs to be assembled. You’ll know which one it is because it has the hole for the tap (the lid is the same shape but sans hole). 

On top of your bottom tray, fold out the white cloth. This will stop wormies dropping down into the ‘liquid’ (aka worm urine). Then put your first tray on top and put down a layer of newspaper. I didn’t get why – just do it! Then put in your layers of compost, spread it around and pour your worms on top. Try not to gag – there are lots of them!! But they very quickly burrow away.

Then get your kitchen scraps and lightly cover a corner of your tray (about ¼ of the tray surface). Sprinkle with a tablespoon or so of lime.  Come back every week and add another wee pile of waste next to the last pile. Katie C and Katie H reckoned it could be three months – or longer – before that first lot of waste disappeared.

For this reason, you may want to get your other layers going simultaneously. Bruce said you should get compost and buy more worms for each layer but Katie C just adds the next layer on and fills it with waste and the wormies burrow up and locate the food as it disintegrates.

Once you’ve got a layer sussed, lay some wet newspaper or a wet tea towel or cotton t-shirt over top. This will keep the ants out. If your farm gets too dry, wet the paper.
Put one empty tray and your lid on the top.

Maintenance

If your vermihut starts to stink, it’s too dry. Give it a sprinkle with a hose or move it out into the open where it will get some rain.
If the food isn’t disintegrating, it’s too wet. So move it under an eave for a bit.
If you get fruit flies, use lime.
A worm farm of the size we’ve got should take about 1 small bag (3 litre size) of waste every 2-3 weeks. So you’re likely going to need a compost pile as well to get rid of all your household scraps.  
You may end up feeding your worms once a week or so.
Utensils to have near your worm hut might include a sock for digging around in the compost, the container of lime and something for scooping it out, and an ice cream container for collecting the liquid.

Harvest

To get your compost out, put the tray in the sun. All the wormies will burrow in deep and you can scrape the rich compost off the top. Alternatively feed them in one corner and as they all head for the food, dig up the vermicast compost in other parts of the tray.
Remember: the compost worms won’t survive in your garden so it’s worth the effort to extract them from the compost before you harvest it.

Once a month, open up the tap and drain off the liquid. Mix this, at a ratio of 1 part worm wee to 10 parts water, and apply to your garden as a super-effective fertiliser.

Other compost

This whole process may get you and your garden slave - I mean, partner - excited about a compost pit. Remember to use treated timber, turn it regularly with a pitchfork, and don’t forget to layer the green and brown waste.

Keri