Now place in the hand of the same gentleman a selection of shredded plastics, leather and glass. I wonder what his words might be. “What is this rubbish?” or maybe something stronger.

Many of us appreciate the benefits of digging in compost and mulching the garden. Organic matter is fundamental to the health of plants. Unfortunately one of the most widely used mulches by the home gardener is becoming a mine field of shredded garbage. How does this happen?

Most councils offer a great service nowadays. You can drop off a load of garden waste at a low cost, sometimes even free. They will mulch it, sit on it for a while and sell it back to you as composted mulch. It’s an ideal way to reduce landfill while providing a benefit to our local environment. But, as with most ideals there is a down side.

Green waste should only contain compostable material. Unfortunately some people irresponsibly throw other rubbish in with their green waste. This can lead to many problems down the track such as machinery damage, injury and increased rubbish in our home gardens and eventually, in the waterways.

The first of these problems occurs in the processing. When the tip has gathered a large enough supply of green waste, a massive machine called a barrel grinder is brought on site. This mean-looking machine has the delicate purpose of smashing and grinding branches, leaves, tree trunks and even pallets and old furniture.

Unfortunately it has some problems with slabs of concrete, rocks and steel such as star pickets. When these enter the machine, the best outcome is down time, the worst is injury to the operators. Some of these foreign bodies may be detected before mulching, though many will slip through the net. Plastic, leather and glass cannot be detected. They too will be crunched up and left to decompose, which of course they won’t.

When you buy your load of council mulch it will often contain many of these non-biodegradable and unsightly elements. As your mulch breaks down all that will remain is the rubbish. If you are a conscientious gardener you will clean up the rubbish and dispose of it as land fill. But if time gets the better of you, much of it will end up washing into creeks and stormwater systems then out into the ocean.

The smaller the piece of rubbish the harder it is to control. Broken glass in the mulch will remain in your soil and will stay sharp for a long time. You, your children and any future owners of the property will risk injury when working or playing in the garden. So, when preparing your next load of green waste to go to the tip, take the time to remove anything that shouldn’t be in the load.

If you employ a gardener, ensure that they do the same. Call it insurance against future wasted time and littering. Together, we can make council mulch the wonderful product is was always intended to be.