soil food web. But in our perennial gardens (herbs, orchard and perennial veggies) it’s generally a different story. Having the soil covered permanently (or close to it) prevents evaporation, fosters a stable soil food web and will generally improve the health of all plants. So in our garden, rather than only relying on buying mulch we also grow living mulches that have multiple benefits… They reduce evaporation, can provide nutrients to the soil, attract bees, fix nitrogen and help stabilise steep slopes. Here are four examples of living mulches we use in our own cool temperate garden…
VetchVetch (Vicia sativa) is a nitrogen-fixing ground cover that (to our delight) actually volunteered in our garden. We foster it in our herb garden where it fills in any gaps between plants and adds to the colour of the area with its purple flowers (not flowering at the moment).
ComfreyWe’re big fans of comfrey (Symphytum) and plant it amongst our orchards and globe artichoke patch where it also helps stabilise the slope. It’s deep tap root can “mine” minerals into its leaves which we then chop and drop beneath our fruit trees where they release these minerals into the top layers of the soil. We’ve written extensively about comfrey and its uses – see our past blogs and photos here.
CloverWe use white clover (Trifolium repens) throughout our small edible forest garden. This quick growing, nitrogen-fixing ground cover is super hardy and popular amongst the honey bees. They’ll flock to the flowers, which of course ensure the fruit trees nearby benefit from pollination. FYI – never plant this in your annual veggie patch as it’ll become invasive and you’ll never get rid of it!
Mixed floralEasy on the eye and a hot spot for the bees, a mixed floral living mulch system is a great way to go for both the soil and often your tummy. A lot of these flowers are edible, including the nasturtium and calendula flowers – add these to your salads (and more) and you’ll end up eating rainbow dishes!
What about native plants as living mulches?Good question. We currently have two native plants we use in our garden as living mulches – the creeping boobialla (Myoporum parvifolium) beneath our young grevilleas and tea trees and creeping saltbush (Rhagodia spinescens) which we’ve planted beneath our young olives – this last one is recognised as a local bush tucker plant as well.
The boobialla grows incredibly close to the ground, while this particular variety of salt bush will grow to around 30cm before spreading out – they’re both beautiful and vigorous plants.
Obviously there are many more plant options available to you depending on your climate and context. The key thing to aim for is to choose plants that benefit, rather than compete with one another. As a general rule, most ground cover plants will have shallow root systems, meaning they’ll be suitable as a living mulch around fruit trees or larger plants that generally have a deeper root system.
At the end of the day, maintaining bare soil in your perennial crops is a lot of work (think weeding and watering). Why bother when you can grow a living mulch – the benefits are many and while it still requires input from you, it’s significantly less and the rewards and more!]]>