Lawns can be a bit of a contentious issue in Australian gardening circles. Are they water-hungry, energy-intensive, herbicide-laden ecological wastelands, or a beautiful, lush antidote to our dry hot climate? Perhaps a bit of both?
Love them or not, there are lots of lawns growing in our neighbourhoods for now, so, let’s look at what we might do with all those lawn clippings that mount up, and ask ourselves “can we compost that?”
Most of us know just how sludgy, stinky and heavy a pile of fresh cut grass can get if we leave it mounded up for even a day or two. This is telling us some things about how lawn clippings will behave in our compost piles.
Firstly, they are nitrogen-rich, that’s what the stinky is telling us. Secondly, they are quite wet (particularly in spring), that is what the sludgy lets us know. And, thirdly, they are very dense, adding little or no aeration or structure to our compost, that is what the heavy is saying. All this adds up to an ingredient that is going to take some care to compost well.
We are going to need some very carbon-rich ingredients to balance our grass clippings’ super-high nitrogen levels. Wood chips, straw and autumn leaves will all do that well (in that order, from highest carbon to lowest). These ingredients will also help balance grass clippings’ overly wet qualities too, and will all add some aerating ‘structure’ to balance their overly dense, heavy qualities.
We also get some great additional ‘structure’ from woody garden prunings, chopped up into short lengths (10cm or under is best).
Careful layering is essential. Grass clippings layered too thick will give us soggy, airless sections in our pile, so keep layers thin. Even consider pre-mixing clippings with some of the structurally balancing ingredients listed above before adding them to the pile.
If we are struggling with an overload of grass clippings, perhaps we might ask, do we really need quite as much lawn as we have? Or, put another way, do we really enjoy mowing that much?
We might also consider what lots of old-timers used to do and just let the lawn clippings lay where they fall, a technique that works particularly well with push-mowers. Using this approach, the lawn – and soil it grows in – effectively fertilises itself, getting healthier and more resilient as we mow.
And, before we leave the topic of lawns, I do have two things to ask. If you are buying fertiliser for your lawn, are you sure you are comfortable with using such a precious, energy-intensive and fought-over resource as nitrogen fertiliser just to keep a private lawn green?
Lastly, please can we reconsider using any ‘synthetic auxins’, a group of broad-leaf herbicides, not broken down in compost or in animal’s guts (see earlier conversation on this topic)? Sprayed grass clippings are often the source of the contamination, and go on damaging plant growth and whole gardens, sometimes for years after their initial use.
– Joel Meadows works with *Yes In My Back Yard, (YIMBY), a community-scale composting initiative in Castlemaine and surrounds. Send questions or comments to hello@yimbycompost.com, or to book in for a compost workshop.