A tree stole my compost!
Managing Tree roots in compost piles
Does your compost pile never seem to fill up, always seems dry and powdery and no matter how many kitchen scraps and garden prunings you put in it, never seems to be rich or crumbly?
It could be that a tree is stealing your compost.
Now, don’t write me off too fast, I’m not suggesting that as you sleep, trees are sneaking into your yard, lifting the lid of your compost bin and pilfering the moist, nutrient-rich scraps. But, trees have a subtler way of finding water and nutrients; that’s through their roots.
Large trees in our yards, or even some distance away, have the amazing ability to find and grow towards sources of water and nutrients. In our Central Victorian gardens, a compost pile might just be the best source of these limited resources for many meters around.
Once a tree has its fibrous mat of roots up into our compost pile it is almost impossible to make the pile wet or nutrient-rich enough to get it to compost well.
If this sounds like your compost, don’t despair, there are still a few things you can do to make great compost while having a peaceful relationship with your neighbouring trees.
The simplest approach might be to compost up off the ground. Lots of YIMBY* composters have their bays on wooden pallets covered in shade cloth or fine mesh. Tree roots can’t grow across the air barrier. Composting still works fine and worms still find their way into the pile.
Because tree roots take some time to find and grow up into our pile, moving the location of our compost to a new spot in the garden each time we start a batch can be an effective strategy. This might also encourage us to turn our compost more regularly which could be a little bonus of this approach.
Lastly, if you have the perfect compost spot in your garden, and well-built bays that you really don’t want to move, you might want to take on the bigger job of putting in some root barriers below the ground.
I have dug down 700mm and buried corrugated iron vertically around compost bays or garden beds I wanted to protect from tree roots. It won’t last forever or keep a very tenacious tree’s roots at bay indefinitely, but can work for quite a few years.
Next week, Mikaela Beckly will teach you how to make your compost like a lasagna.
Author: Joel Meadows
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