Composted Manure


Hello! I attended Through the Garden Gate in Wychwood last weekend. I met a lovely master gardener at one of the houses who advised me that commercial composted manure these days is of poor quality – that it is often filled with fillers like peat moss, and that I should look for compost directly from farmers. When I got home, I tried googling where to get some in southern Ontario but don’t know how to trust the sources. And is it bad to buy composted manure that has soil and peat moss in it? Can you share where the TBG sources it’s compost from?


Thank you for contacting the Toronto Master Gardeners. We’re so glad you were able to enjoy the beautiful gardens in Wychwood.

Water, air, nutrients, and physical support are provided to plants and organisms in a productive soil. The Toronto Master Gardener gardening guide on  Soil Fertility provides information on improving your soil.  As mentioned in this guide, the best sources of organic materials come from your own garden, including backyard compost, leaves, and plant debris. This guide also recommends composted animal manure as one type of organic matter to improve soil fertility.

Composted manure is a renewable and organic resource that helps to improve beneficial organisms in your soil and increases water holding capacity to improve soil structure. Generally, many commercial composted animal manures (cow, sheep) do not contain any additives. However, as you mention, there are some commercial composts (sea, shrimp, bark) and composted manure (cow, sheep) that do include sphagnum peat moss. Check the labeling on the bag (or ask your gardening supplier) to find out what’s included in the contents. Composted manure, with or without added peat moss, will improve the quality of your soil. Make sure you use “composted” animal manure, as “fresh” manure has a high concentration of nitrogen and ammonia that may burn and dehydrate plants. Be careful when purchasing un-cured animal manure directly from a farm, as fresh or incorrectly composted, manure may also contain invasive weed seeds, or worse, harmful pathogens. Whenever you apply organic amendments to enhance your soil, ensure the product has a consistent texture, moisture content and a pleasing, earthy smell.

Much of the compost created from the City of Toronto residents’ yard waste and Green Bin collections is used in our parks and gardens:  Toronto Recycling Organics.  You can obtain some of the same compost during Toronto community environment days. 

Additional resources:

Compost vs. Manure

Happy Gardening.