Composting onion skins – with & without biodynamic remedies

One of my most enjoyable compost experiments at the moment is using bags and bags of onion crop waste.

Why onions??

I live on the edge of the Franklin district, where about 25% of New Zealand’s vegetables are produced.

That’s a lot of food!

And it’s also a lot of food waste, some of which I am sure would make interesting soil.

Method:

Onions collected on 5th September 2023

I’m using these terracotta pots from Pacha Compost to hold a bag of onions, along with about the same volume of cow manure.

One pot got the biodynamic cow pat pit preparation (CPP): I stirred up a half bucket of CPP and soaked the onions in it before filling the pots.

Why the 1:1 ratio of onions to cow manure? I did a Google search and found this piece of research. No need to reinvent the wheel, right?

The experiment began on September 6th, 2023.

Updates at 24th September (day 18)

It’s only been a few weeks, so it’s way too early for any conclusions, but when I had a quick peek in the pots after two and a half weeks, there was a noticeable different in compaction from the biodynamic blend:

See how the level is much lower?

The onions were softer and the layers separated easier, but other than that both batches looked and felt the same: the manure is very fresh, and I’m keen to add in some plant material to help speed things up.

What to add?

It might be one of the go-to compost activators:

• Comfrey
• Borage
• Dandelion
• Yarrow
• Chamomile
• Stinging nettle
• Valerian

Or it could be one of my other favourite herbs. I used Geranium in a third pile that included all my tomato vines (what I’m calling my salsa compost), and the soil smells amazing.

Next step 11th October 2023 (day 35)

Observations:

The biodynamic batch has once again shrunk faster — both vertically and also it’s pulled in from the edges of the pot. It’s almost like the non-biodynamic batch is at the point the biodynamic batch was at two weeks ago.

Is the biodynamic compost faster?

I always use Nature Communication practice (from Saskia von Diest of Ecofluency) to tune into the specific compost and ask what it wants or needs.

Here are my notes this week:

• Plants to mix into the onion compost: Gorse, Geranium, Borage.
• Plants to mix into the salsa/onion compost: Gorse, Aloe.

Stay tuned for updates as I learn more.

-Katrina

Ideas for innovative edible gardening solutions using biodynamic methods to make ‘soil with soul’ is what New Zealand needs right now. For tips, advice and online courses go to www.blueborage.co.nz or get in touch by email at katrina@blueborage.co.nz