DIY Worm Farm, Free Soil Conditioner
Worms and gardens go together like peaches and cream (though are somewhat less edible...). Worms are the ultimate composters, eating through decaying plant material, pooing/weeing out the leftover nutrients and solids, and creating a much better product that is reused by growing plants. Worm castings (poo) from a 'farm' or 'hotel' contain nutrients that are readily available for plant uptake, as well as millions of bacteria from passing through the worm's gut. Being made of organic matter, they also assist gardeners by improving soil water retention and structure. Worm juice/tea (wee) is a concentrated liquid form of these bioavailable nutrients. Because of all these amazing functions, worm castings are both fertilisers and conditioners of the soil!
Despite having three different composting systems in my garden, I decided this spring to make my own worm farm as it means I can improve the soil a) cheaply, b) organically and c) waste-free. We eat such an enormous amount of veggies so I will probably still put some scraps in our Bokashi bin, while citrus and onion skins will always go into my cold compost as worms hate them! As my worms breed, they will eat more and so I will be able to add more scraps and therefore harvest more castings.
Worm farms come in all shapes and sizes and there are many different structures - single or multi-level. In an afternoon, James and I made the one pictured below. It now lives in the backyard, not far from the kitchen, in part shade. Here's the link to the instructions I followed (which were REALLY easy) from Working Worms. Below is a list of my materials used and rough costs. Note that you can definitely make this from recycled materials if you can find them, like polystyrene tubs or buckets!
- 3 medium-sized* black plastic stacking tubs ($18 each from Bunnings)
- 20mm plastic outlet tap (about $3 from Bunnings)
- 20mm nut ($1 from Mitre 10)
- Leftover piece of plywood for the lid
- Leftover shade cloth to fill the gaps between levels
- composting worms ($40 for 1000^ from Ernesto at Geelong Worms)
- Drill and 6mm drill bit
- 8 used 7" plastic pots
Total cost: $98
*You can choose whichever size containers you like to suit your needs (i.e. amount of scraps produced, amount of castings desired)
^It's recommended that you start with at least 1000/250g to get your farm going
Once you're up and running, you can use the castings and worm wee on your garden. Castings can be directly applied in small amounts (like poultry poo) or you can strain some through a stocking in a 10L bucket to make a tea. Collect your wee regularly via the tap at the bottom and make sure you dilute it before application - most people suggest to make it the colour of weak tea. In my opinion, it's best to apply these a) when planting new plants, b) in the growing season and c) as a hot compost activator (wee). To find out more about vermiculture and worm farms, including troubleshooting, read on here. I'd love to see your shared thoughts, questions or own photos on SEED's Facebook page, Instagram @seedblog, or in the comments below. Happy gardening!