I was putting a finished compost pile out on the garden recently, but as I was forking it into the barrow, I realised, with disappointment, it was the worst compost I had made in quite a few years!
The ‘finished’ compost was dry, woody and full of fine root filaments, not the rich, moist, greasy, ‘humic’ goodness I am used to producing. So, what went wrong?
It didn’t take too much digging to work out at least four thing that had led to this being such a bad batch of compost, and each of them are things I have written about in this column.
The first mistake was too much wood chip in my recipe; I had been experimenting with wood chips and had leaned too heavily on this carbon-rich, lignin-heavy ingredient. In moderation wood chips are great, say about five per cent of the compost volume, but I had probably used double this or more, leaving the finished compost with way too much unintegrated wood chip.
The second mistake was a common summer one, letting curing piles dry out too much. With lots of sun, lots of wind and hot dry conditions (all of which we have had an abundance of) composts can dry over several weeks. Although I had watered the pile, it simply was not enough to compensate for the evaporation from the pile in our long, dry summer.
Just checking the moisture at the centre of a compost pile can be deceptive, as this part will hold good moisture longest, don’t forget to check moisture at the sides and halfway between too. In dry weather a good water every few weeks is recommended.
The third problem was that plant roots had found the compost pile and were mining it for moisture and nutrients. The further I dug into the pile the more of these fine root filaments I found, and the dryer and more depleted the compost appeared.
Some big trees will strip a compost completely bare, in my case it was perennial plants around the compost, so not as bad, but still a depletion of the nutrient and moisture in the compost.
The fourth mistake was leaving the compost too long. This pile would have been ready at least a month earlier, but summer gardening and other responsibilities being what they are, I had not got to it and left it longer than was ideal.
This longer wait time also exacerbated the drying out, as well as the damage to roots did to the compost as well.
This batch of compost was not really good enough to put on the veggie garden, but was okay for under fruit trees and berry canes, so it didn’t go to waste, still, it was not as good as it could have been, and I learned (or re-learned) a few good lessons along the way.
There are detailed articles on each of these issues (wood chips, moisture monitoring, tree roots and finishing/curing) on the YIMBY website.
– 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.
