Adding Composted Manure to Soil


Hello Master Gardener Friends ~

I would like to add composted manure to my gardens which are already full of plant roots and tree roots, which make digging next to impossible. A recent Toronto Star article recommended digging the manure in to a depth of 6 or 7 inches, which in my case is just physically impossible. In reviewing the TMG Guide on “Soil Fertility” it seemed to suggest that disturbing existing soil by digging may not be a good idea. My question: Since realistically I can’t dig this manure in but would just spread it on top of the existing soil, would I be achieving anything, or just wasting my money? Many thanks in advance for your thoughts! Barbara


Thank you for contacting the Toronto Master Gardeners concerning no-dig gardening.

There is a wealth of information on our website concerning this topic. The following is a summary from a number of our archived posts:

Originally, tilling was used to break up and loosen soil, turn up weeds, and quickly incorporate soil amendments. The thinking is that as long as the soil is loose and free of weeds, something should grow! However, recently  researchers have found that tilling destroys fungal networks and the sticky exudates of soil organisms that hold soil together. In fact it has been shown that tilling  destroys humus, the organic component of soil that is necessary for plant life.

No-till gardening maximizes the health of garden soil and minimize weeds, creating a much better environment for growing vegetables.  For example, preserving physical soil structure is important – this impacts drainage/retention of water, erosion, and crusting on the soil surface.  No-tilling also encourages earthworms and microbes – which contribute nutrients – to thrive. On the other hand, tilling soil can harm the soil, for example it can promote erosion, bring weed seeds to the surface, and disrupt soil aggregates (clumps) – the latter contributes to soil compaction.”

Charles Dowding is well-known in the UK for his “no-dig” gardening expertise.  There is a lot of helpful, free information on his website – including his blog and Beginner’s Guide.

There is lots of great information on-line about no-till gardening, here are a few links:

Try to remember that soil is a living thing and the less you damage it, the better It will take a few years to achieve healthy soil through no-till gardening, but it will be well worth it in the end.