To Mulch or Not to Mulch

A Thought-Provoking Question

As we were shovelling mulch into wheelbarrows from the large pile of green waste compost that had been dumped in the entryway, my colleague working alongside me posed a profound question: Is it necessary to apply mulch to borders? What are the benefits and why are we doing it?

I paused before responding, realizing that my stance on mulching had evolved over time. A couple of years ago, I was convinced it was essential for a healthy planting scheme. I saw it as a viable alternative to applying fertilizer, which I already questioned as being necessary for plant health. I believed mulching provided nutrients, improved soil structure, suppressed weeds, and contributed to a neat and well-maintained garden appearance. While I still hold this true, I have started wondering whether there is a different way in going about providing these benefits to the garden. 

The Costs and Challenges of Mulching

Home-made compost, mostly from Kitchen Waste

While mulching offers many benefits, such as improving the soil structure and soil ecosystem, it also comes with significant costs—both in materials and labour. In smaller gardens, the effort to shift mulch from delivery points to planting areas is manageable, but in larger gardens with extensive borders, this becomes a major expense.

Home composting is one way to mitigate material costs, yet most gardens do not generate enough organic material to produce the needed volume of compost. Additionally, many gardens lack the space to accommodate compost bays.

A More Sustainable Approach

In response to these challenges, I have started experimenting with an alternative method in my own garden: using the plant material cut down in winter—such as herbaceous perennials and fallen leaves—to mulch borders in situ. Instead of removing and later reapplying organic matter, I simply cut the plant material into small pieces and reapply it to the border straight away.

This method not only provides shelter for insects and other wildlife but also follows a natural decomposition process, gradually releasing nutrients back into the soil as the material slowly decomposes.

Learning from Nature

This approach mirrors what happens in nature. Trees shed their leaves, which decompose and return nutrients to the soil, feeding the tree’s own root system. In contrast, traditional horticulture often disrupts this cycle. We remove plant material from our gardens, either discarding it or placing it on a compost heap, only to later reapply or purchase mulch to replace the lost organic matter.

By shredding or cutting plant material and leaving it in place in our gardens, we eliminate the time, labour, and cost associated with removing material and reapplying it at a later stage as compost or manure. This method aligns more closely with natural ecological cycles, reducing our reliance on external inputs.

Rethinking Our Gardening Mindset

Beyond the practical and financial aspects, I believe we need to reassess how we care for plants. Historically, the ideal garden has been one of lush, vibrant, and meticulously maintained flower borders, achieved through fertilizers, abundant watering, and pest control.

However, in the context of sustainability and biodiversity, we should consider shifting our mindset. By selecting the right plants for our gardens and exposing them to a certain degree of stress, they can develop resilience. More robust plants are naturally less susceptible to pests and diseases and more adaptable to fluctuating weather conditions.

One way to encourage this resilience is to limit nutrient availability—meaning less mulching. This shift also invites us to appreciate plants in all their stages, finding beauty in their imperfections and arranging borders in seasonal layers to maintain visual interest throughout the year.

A Balanced Perspective

Mulching undoubtedly has its benefits, particularly for traditional planting schemes that require consistent soil conditions and weed suppression. However, I advocate for a different kind of mulching—one that embraces natural processes by allowing plant material to decompose in place. This method not only reduces labour and costs but also fosters biodiversity and enhances soil health in a more sustainable way.

Moving forward, I will continue to experiment with this approach in my own garden and encourage others to explore it as well. While it may take some adjustment—particularly in terms of aesthetics—I believe this method aligns more closely with nature and supports a more resilient, self-sustaining garden ecosystem.