Wormscaping: how to build an in-ground worm farm

We all know that we should be composting more. But it isn’t always easy to find the time or the space to get those worms working for us. An in-ground worm farm might be just the solution if you’re a time and space deprived gardener.

Of course, you could dig a few holes, chuck in your kitchen scraps and let the existing earthworm population get to it… or you could speed up the process with an in-ground worm farm and the addition of some rapid feeding composting worms.

The time-poor gardener benefits from an in-ground feeder doing a big part of the work for them. Nutrients and humus go straight into the ground via the worms, or are washed into the soil below. Should it reach capacity, just pull it up, move it to a new location and bring a little of the worm-rich material under the surface.

The remaining uncomposted material will continue to break down. With the worms carrying most of the organic matter into the soil around them, it really is a self-cleaning system.

If you’re of the “make do and mend” school of thought, you can get started with an old bucket or plastic garbage bin, with a firm fitting lid. Cut off the bottom, drill holes in the sides at various heights for the worms to move freely and you’re ready to go. The lid is essential to ensure vermin don’t sneak in and snack on all your worms!

Another type of DIY feeder is PVC Pipe. Purchase 1.2 metres of 150mm PVC pipe and two screw caps, cut the pipe in half so now you have two 600mm long pipes. Glue all the bits together and drill 50 holes in each pipe. When you place it in the ground make sure the lid is sitting just above the mulch so you can access it easy. Alternatively there are ready-to-assemble feeders on the market.

Setting up an in-ground feeder shouldn’t take more than an afternoon:-

  1. Find a place in your garden that is easy to access and ideally has plants that will benefit from the worms improving the soil and adding nutrients.
  2. Wet the soil where you are planning to position the feeding station; moist soil is easier to dig and less likely to collapse in on itself.
  3. Dig a hole wide and deep enough to place the feeding station with only 3-5cm above the surface.
  4. With the lid on backfill using the previously removed soil and press down gently around the outside.
  5. Add bedding material before adding your worms. About 5cm depth of shredded cardboard soaked in water, wet newspaper, moist coir or similar. 500g of composting worms should be plenty to get you going.
  6. Cover them up with a layer of wet newspaper. Replace the lid and wet the soil surrounding the feeding station.
  7. Let your worms settle for a couple of days before adding any food. Then start adding scraps. Only feed worms fruit and vegetable scraps, avoid meat and dairy products, citrus and onion. You can make it easier for the worms to digest scraps by chopping them up as small as possible.

It will take some time to get things going so be patient and try not to overfeed them. This can result in things getting a little smelly.

Keep the area around the in ground feeder moist and remember to add in some fibrous material to ensure your worms have enough oxygen. Shredded cardboard or chopped straw works well.

The resulting vermiculture should have your garden thriving, you’ve prevented lots of material heading into landfill to create methane gas and you haven’t had to spend a fortune or devote hours in the process.

For professional advice on setting up an in-ground worm feeder, contact us – The Greenscape Collective.