The City of Toronto's Compost Provision Program
Compost is the natural biological decay of plants, animals and micro organisms produces a stable soil like material referred to as compost.
In nature, composting is a continuous process that occurs gradually over many years. In society, we have learned to control and accelerate this process. Materials that were once considered wastes, such as leaf and yard materials and source separated organic materials can be processed safely and efficiently to produce valuable compost.
The carefully controlled composting process eliminates pathogens and weed seeds and produces a product that doesn't smell and can be used safely. Before leaving the composting facility, City compost is tested to ensure that it satisfies provincial requirements for safety and quality. The compost is a beneficial soil amendment and is safe to use in gardens and on lawns.
- Compost is a source of organic matter, essential plant nutrients and beneficial soil micro organisms.
- Compost improves soil structure and fertility and adds organic life to the soil.
- Using compost is a best plant health care practice. Compost facilitates healthy soil and healthy soil grows healthy plants. Healthy plants are in a position to withstand stress caused by the weather (heat, drought) and pests (weeds, insects and disease).
Use compost as a soil amendment by digging the material into the soil before planting flowers, vegetables and trees as well as for new lawn establishment.
- Flower Beds
For existing flower beds, add about 2 1/2 cm (1”) of compost and work it into the soil using a rake, hoe, shovel or rototiller. Water until the entire root zone is saturated. For best results with new beds, add 2 1/2 to 5 cm (1” - 2”) of compost and rototill to at least a 12 cm (5”) depth. Plant and water accordingly.
- Vegetable Gardens
For vegetable gardens, apply about 2 1/2 cm (1”) of compost and incorporate into the soil to a depth of 12 cm (5”) with a rototiller or by hand. For poor soils, you may need to apply compost on a yearly basis until the soil has improved to your satisfaction. Do not over apply compost because many vegetables will not produce high yields if excess nitrogen is in the soil.
For tree planting, rototill an area about 3 to 5 times the diameter of the root ball of the tree to be planted. Add about 30% compost by volume to the area and mix thoroughly outside the hole with the native soil. Place the tree into the hole and use the compost amended soil mixture as a backfill around the root ball. Remove excess soil and water thoroughly.
For lawns that are going to be seeded or sodded, apply about 2 1/2 to 5 cm (1” - 2”) of compost and rototill to a depth of 12 cm (5”). For seeded lawns, apply seed and then a slight dusting of compost to cover seed. For sod and seeded lawns, thorough irrigation is necessary.
Use compost as mulch around trees and plants to retain moisture and suppress weeds.
- For mulch applications around annuals, perennials and other landscape plants, a 5 cm (2”) layer of compost is optimum. Apply compost and rake to achieve an even application. Avoid over or under mulching because other problems can arise, such as smothering of root systems. Arrange mulch so water flows away from trunks, reducing chances for crown rot. Finer-textured composts do not suppress weeds as well as coarse-textured composts.
Use compost as topdressing for existing lawns.
- For best results, aerate the entire area before topdressing using a commercially available aerator. For topdressing, spread 1/3 to 1 1/4 cm (1/8” to 1/2”) of mature compost evenly over the area using a rake. Water thoroughly. The water helps the compost move through the thatch layer to the soil surface and into aeration holes where it can help retain valuable moisture.
Use compost on houseplants, as part of a seed starting mix and to use with other potting materials.
Make a liquid compost or “compost tea” and use it as a soil drench to keep plants healthy and vigorous throughout the season.
- Liquid compost provides an immediate boost for your plants. It’s simple to make and easy to use. Fill a cloth bag with dry compost and put it in a barrel or bucket of water. Your mixture should be about one part compost to five parts water. Let it steep outside for a week, swirling it around a few times each day and making sure that the “tea bag” keeps submerged. Each week, you can then pour the “tea” over your soil around your plants. Put the left over compost from the bag either back into your backyard composter or spread it in the garden.
Excerpts used with permission of The Composting Council of Canada and the US Composting Council. For more information on composting and the Composting Council of Canada, please visit: www.compost.org