Worm Farming, Workshop Notes
If you are serious about growing good quality food for yourself, your whanau and maybe some friends or neighbours as well, putting organic matter back in the soil is vital!
There are many ways to do this, listed here in order of simplest to more complex, least effort to most, small garden solution to larger garden solution:
Using worm tubes to add organic waste directly into the soil.
Worm farming and adding the vermicast to the soil
Making bokashi and digging that into the soil (eg by double digging, bokashi only being added to the trench, not the surface)
Making cold compost
Making hot compost
You need to do at least one of these if you are growing food!!
When you become a composter, (another addiction, I warn you!), you will actually be horrified to think that once maybe you threw your food scraps in the bin.
And if you don’t grow food – you still need to either use one of these methods to keep your food scraps OUT OF LANDFILL or at least give your unwanted organic matter to someone who will!
NO food waste/garden waste should be going to landfill. NONE!!
There is an awesome ap called Share Waste https://www.sharewaste.org.nz/ where you can become a donor or receiver of compostable waste. As a receiver, you can say what you do and don’t want to receive. If you have food waste to dispose of, you can find someone who will take it!
With or without the app though, please DO SHARE YOUR WASTE!
Worm farming
Not everyone has the energy, materials, space or the inclination to make a hot compost.
But most people CAN manage a worm farm. That’s why I am a big fan – because they are so do-able! Plenty of people use them on Aotea. If you have one that is out of service - either start using it again, or contact us to rehome it!!
Worm farms come in many sizes, and the smaller ones, like the Can of Worms, are perfect for single people. Larger ones, like the Hungry Bin, or getting bigger again, DIY worm farms in baths, deal with a lot more organic waste.
Some people make hot compost with garden waste, AND use worm farms to deal with everyday kitchen waste. So many options!
Worm farms give you an amazingly high quality fertiliser for the garden – vermicast! It is very concentrated and rich in nutrients, and has an extremely diverse range of beneficial microorganisms.
It is useful to understand that worms actually eat the micro-organisms that are breaking down the organic matter you are adding to the farm. They can’t actually eat food scraps or cardboard. So what you want to do is feed the microorganisms a balanced diet, a bit like setting up a mini compost heap (but we don’t want it to get hot ofcourse!). When all the biology is active the worms will be very happy!!
That brings us back to the principle of the 30:1 carbon to nitrogen ratio that we discussed for compost. But you don't have to get too fussy about it.
Great food for worm farms:
Any fruit/vegetable scraps, trimmings, peelings etc remove stickers from fruit
Cardboard and paper (soaked before adding) Remove tape form cardboard.
Coffee grounds
Animal manure: chook poop (in small quantities/thin layers - it is very strong) , cow manure (best)and sheep manure (make sure they haven’t been drenched for parasites). Horse poop ok but tends to have lots of weed seeds. Better to hot compost it.
Semi-broken-down compost
Be careful of paper towels and teabags: many brands have plastic in them to give them strength. AVOID! (Earthwise paper towels are plastic-free, Dilmah teabags are biodegradable).
Most instructions tell you avoid citrus and onions, but as long as you aren’t adding huge amounts to the worm farm, it’s OK. These will break down through the action of micro-organisms, along with everything else.
Very Important:
Worm farms should be kept quite moist at all times, (wetter than a compost heap) as worms breathe through their skin, and need to be able to slide around.
However, they must never get water-logged (ie standing water in the worm bin) so must have drainage
Keep out of direct sunlight/intense heat in summer but move into a warmer spot over winter. Close to the kitchen is good - makes it easy to remember to use it!!
Firstly: to start off a new tray, the recommended rate of worms to add is 500g to 1.5 kg worms per square foot of surface area. The more worms, the faster they will work through the feed. So if you won’t be adding much food to the worm farm, just add the 500g. They will breed up anyway and adjust their numbers to the amount of feed they get.
The first tray and the lid go on the bottom stand - which collects any liquid that drips out – and the other trays are added as the lower trays fill up.
I recommend leaving the tap in the bottom collector stand permanently open and draining into a bucket, especially if you keep the worm farm outside. in a heavy rainfall, the bottom stand can fill pretty fast, waterlogging the worm farm.
After setting up, the worms will take a week or two to establish. Check them every few days and observe how the top layer of feed (eg veg scraps) looks. If it looks quite rotted down like the compost and the worms are burrowed deeper underneath, it is time to add another 1-2 inch layer of feed.
Check how the worms look too. The worms are healthy if they are pinky-red and nice and plump.
If they are underfed, they will shrink, but usually they will survive periods of low feed as long as they don’t dry out. (If you’re going to be away for some time, there is nothing like a few cow pats to keep them busy and happy while you’re gone!)
If the farm is too wet and getting anaerobic it will smell bad and the worms will look yellowish. In that case, add shredded dry cardboard or dead leaves and bury it in the feed to absorb the excess moisture.
As you keep feeding the worms, that first bottom tray will start to fill up with vermicast and semi-broken down feed. Then it is time to add another tray on top of the first. You can line it with some wet cardboard again, and some fresh feed. The worms will gradually wiggle up into the new tray and feed. Once the worms have left the bottom tray the vermicast can be harvested and used – usually around 2 months after starting up.
Using Vermicast and Vermi liquid
So how do you use vermicast and liquid (worm wees)? And when is it ready? And why is it so good for the soil and for the plants?
If you have a stacking system where a new tray with bedding and food is placed over the older, full tray, the worms will take 2-3 weeks to migrate from the lower tray up to the next one through the holes.
The tray of ripe worm castings below will be dark browny black, and there should hardly be any worms left in it. If you dig your fingers into the worm castings, they will be silky smooth and damp. There should be no bad odours, just an earthy, composty aroma.
The thing about worm castings is that they are a very very concentrated source of highly available nutrients, humus and billions of beneficial micro-organisms.
The digestive process that takes place in a worm farm is amazing! First the microbes – mostly bacteria, but other types as well including protozoans and fungi – digest the organic food you add to the farm- food scraps, cardboard and the glues that hold the cardboard together, manure, eggshells etc. The microbes do this by secreting enzymes through their cell wall to break down the organic compounds (sugars, starches, waxes, proteins, cellulose etc) into a form they can absorb. To us, it might look gross and slimy, but as long as it is aerobic, the microbes will thrive and multiply. Which is what we want!
The microbes then become fat, as they absorb all this highly nutritious deliciousness! They multiply fast and keep going til the food runs out (which you don’t want to happen!). Their life span is pretty short and the dead microbes get digested in turn by others. All this means that each individual microbe is simply loaded with nutrients and as they die, the nutrients are released ready for being absorbed by other microbes, worms or plant roots.
In a worm farm, tiger worms and red wriggler worms (the composting worms) just LOVE this microbial soup and chow down on it. They suck it up along with tiny bits of organic matter through their tiny little mouths. The worms have a special grinding mechanism inside just past their mouth which literally crushes most of the microbes and squeezes out all the nutrient-laden juices -the ultimate smoothie machine! Even disease-causing fungi and bacteria get destroyed. This is food not only for the worms to absorb, but also for the worms’ own microbial gut flora which have their own feeding frenzy.
As all this goop passes through the worms’ gut, millions of the worm’s own beneficial bacteria get inoculated back into it, so when it eventually passes out as worm castings, it is a super-concentrated in plant available nutrients and beneficial microbes.
So when you use your vermicast, treat it like gold! No need to use huge amounts. Probably the most effective way to use vermicast is to dissolve a handful or two in a few litres of water. Agitate gently and make sure little lumpy bits dissolve. The water should be dark black/brown. Then use this straight away as a plant and soil tonic by watering your seedlings with it, or add to your planting holes before popping in your seedlings. It can also be used to inoculate a compost heap when it is past its hot phase.
The semiliquid that drips out can be treated the same way, well diluted. Use it regularly, as it can become anaerobic if left sitting too long.
And if you haven’t got a worm farm yet, might be time to start!! Why wouldn’t you?! Such an awesome way to cycle your food scraps into an amazing resource. Nature’s way!
