Balcony Compost – DIY guide

For urban growers who are limited to balconies and rooftops, it may seem like a challenge to make your own compost. Veganic gardener Marco Pagliarulo, who has a 5th-floor balcony garden in downtown Toronto, came up with an innovative homemade technique for composting in a container garden on his balcony.

A simple do-it-yourself design, the balcony compost has the potential to bring veganic composting to skyscrapers, rooftops, concrete surfaces and contaminated lots. The design has already won first place in Toronto’s container gardening competition, and was featured in the book City Farmer: Adventures in Growing Urban Food.

The concept is quite simple: a bottomless bucket is nestled inside of a larger container. Inside the bottomless bucket, finely-cut food scraps and brown leaves are mixed together, which slowly break down into compost. Between the bucket and the container, soil is added and plants are grown. These plants are automatically nourished by the compost that seeps out of the bottomless bucket. A trap door is added at the bottom of the larger container, so that the composted material can later be removed by hand.

Step-by-step DIY guide

This is based on Marco’s original model. The sizes are suggested minimums, though experiment with the resources you have available.

• Begin with a large plastic container, about 45cm in diameter, with drainage holes in the bottom and a tray for catching excess water. On the side of the container, near the bottom, cut a 12cm by 12cm trap door that can open and close. This is how you will later remove the finished compost.

• Take another container or bucket, about 27cm in diameter and at least 35cm tall. Drill holes all over the sides and lid, and then cut off the bottom of the bucket. The holes will provide passive aeration for the composting material.

• Put 5-10 cm of potting soil in the bottom of the large plastic container. Place the bottomless bucket in the center. Between the two containers, fill this space with potting soil. In this ring of soil, you can grow edible plants. Marco has had good success with nasturtiums, tomatoes, dill and onion.

 

• Over time, add fruit and veg scraps in the bottomless bucket, ideally in small pieces, and avoid adding oily foods. Always add the same quantity of dry leaves (remember, dry leaves can be collected in the autumn from neighboring trees). Stir the compost well to aerate. As the scraps break down over time and leave space, continue to add more scraps.

• After several months, remove the maturing compost from the trap door at the bottom. If it seems like it needs more time to mature, simply leave the compost in a separate bucket for a few months until it is ready to use.

Need a little more info? Check out Marco’s original instructions at www.torontobalconiesbloom.ca/demo.html

Balcony composting tips

• A balcony compost can be large enough to handle the veg scraps for one person, and the resulting compost can provide fertilizer for a balcony garden and indoor plants.

• Aeration is important to keep the process aerobic and to speed up the decomposition. Stir the composting material with a stick (bamboo works well) when you add more food scraps and leaves.

• After stirring, cover the decomposing food with a little soil to keep bugs and odors to a minimum. Marco uses soil from his family’s garden, to give a boost of natural microorganisms that aid in breaking down the food.

• In a Canadian climate, the balcony compost comes to a standstill in the winter, though starts up again naturally in the spring. Bringing it inside can lead to smelly results, so try to find an alternate composting solution in the sub-zero months.

• Remember, a balcony compost is a miniature ecosystem of decomposing organic matter and it requires your attention and care to succeed. Be attentive to the balcony compost, especially making sure that you add enough leaves and stir regularly.

• Aesthetic tip: Marco also adds a smaller potted plant on top of the lid during the summer months, to grow more plants in a tight space and to aesthetically hide the compost bucket.

Want to see more of Marco’s garden? Visit the Downtown, south-facing balcony, 5th floor at Toronto Balconies in Bloom.