Ron evens out the stones that are used to fill the reservoir.

A simply designed, multi-purpose garden bed and worm farm was just what the Neighbourhood House needed. Andrew and his friends whipped up an inexpensive model to serve everyone’s needs.

by Andrew Young
Stratford, Victoria

A few friends and I decided to make a garden bed for the local Neighbourhood House. The garden had to be suitable for a childcare area, easy to maintain, aesthetically pleasing and had to fall within our budget of $100. We came up with the following design.

The box measures 4.8 m long by 60 cm wide and includes a worm farm in the centre. It is made from 150 mm x 25 mm garden edging that cost only two dollars a metre. The lid for the worm farm is made from treated pine fence palings, scrap wood and handles made from cotton rope.

Andrew alternates layers of compost with lucerne.

The worm farm has escape holes at the bottom so if the worms are not fed or if they run

out of water, they can easily escape into the garden beds. This also means that they are spreading nutrients into the root zone of the plants and aerating the soil.

The two garden beds have small water reservoirs that allow the garden to ‘wick’ the water up through capillary action to where it is needed by the plants. If too much water is added then it will overflow to one side.

Box construction

The construction of this garden is remarkably quick and easy. You need four six-metre lengths of treated pine garden edging. One 4.8 metre and two 60 cm lengths are cut from each of the four lengths of wood. On each 4.8 m length, mark two metres in from each end. This is where the worm farm will go. Pre-drill the ends of the box and where the worm farm will be situated. Then screw the sections together. This will make two boxes that are placed on top of each other. Small sheet metal off-cuts can be cut in 28 cm lengths, folded lengthwise at 90 degrees and nailed to the corners for added strength. This is optional.

Worm farm and lid. The Hessian bag keeps the worms cool.

Water reservoirs

Soil is banked up against one side of the box about 10 cm high to direct water to the other side. A 5 cm mound is created on the other side about 10–15 cm from the edge. We used some pieces of scrap wood and soil to make this mound. This is so the water has to reach a certain height before it can overflow the mound. Concrete underlay plastic is then laid along the bottom and back of the box. Make sure to leave a gap along the side of the mound for water to flow off. Also make sure the plastic goes up the ends of the bed but stops short of covering the worm escape holes. Stones are then used to fill the reservoir to the top of the mound (the gaps between the stones hold the water). They are then covered with shade cloth, fly wire or any other material that will stop the growing medium from falling into the reservoir.

The lid

Four 15 cm-wide fence palings are nailed to two scrap lengths of wood to form a lid for the worm farm. The handles are made by drilling two holes 12 cm apart just big enough for the rope. The rope is threaded through to make a loop and knots are tied on the other side. A few pieces of scrap wood are then tacked to the inside of the worm farm to support the lid.

The completed garden is planted out with a mixture of herbs and salad varieties.

Filling the garden

The no-dig growing medium for the garden consists of an initial layer of sheep manure and grass. I don’t put these on top as weed seeds grow too easily. It is then topped with shredded newspaper followed by alternating layers of compost and mulching lucerne. Blood and bone and/or worm castings can be added to give it a good kick-start.

Establishing the worms

The worm farm box is first lined with cardboard on the bottom. Be sure not to cover the worm escape holes. A bedding layer of shredded newspaper, hay or old leaves is added; it is then ready for some worm food. Weeds, soft plants and kitchen scraps such as fruit and vegetables, teabags and coffee grounds are added. Place the worms on top to work their way down into the food. A Hessian bag is placed over the top and they are given a quick watering to make sure they stay moist.

Planting out

The children in the childcare centre got their hands dirty planting a range of herbs and salad greens to be used in the Neighbourhood House. The plants included mint, oregano, rosemary, sage, chives, lettuce and lemon balm. These plants were chosen because they displayed various different sensory qualities that hopefully would be appealing to children. They also come in handy for cooking classes or herbal tea.

Costs and Materials

• 4 x 150 mm x 25 mm treated pine at $12 each
• 1 pack treated pine screws at $4
• 2 x 1.8 m treated pine fence palings at $2 each
• A few pieces of wood off-cuts
• 3 m x 4 m concrete underlay plastic $10
• 4 x 10 litre buckets of stones or scoria
• Scrap pieces of shade cloth, fly wire or Hessian
• 1 metre of thick cotton rope at $2
• 1 pack 25 mm nails at $4
• 1 x bale of mulching lucerne at $12
• A couple of bags of manure
• Grass clippings (preferably composted)
• Torn up newspaper/cardboard
• A few handfuls of blood and bone
• Worms and worm castings.