Every time I plant a seed

What you got that I don’t know? The contents of commercially available potting and seedling mixes include wetting agents, slow release fertilisers, growth stimulants and who knows what else – but you have no idea what it is. Is the wetting agent some irresponsibly mined peat moss, or is it some chemical leaching plastic? How many chemicals are in the fertiliser? Not that a seedling needs a ton of fertiliser anyway. So to make sure you stay true to your roots, organically speaking, you sometimes have to take matters in your own hands.

We already had a bunch of cuttings in the greenhouse planted in really lifeless used how many times potting mix. So in Milkwood’s Introduction to Organic Market Gardening course we learnt how to make our own organic seedling mix, to be used for seedlings or cuttings. When I asked Olivier, our course instructor, about it, he said we should transplant them into a proper mix as soon as possible. So it became one of those projects listed in my course notes with a big bold red circle around it.

Now of course, when you attend such a course, they have all the materials readily available and with the right containers to work with too. So my first challenge was to source the raw materials, organically, ecologically responsible and cost effectively. Eventually I located a large bag of organic vermiculite from a Melbourne aquaponics dealer, compressed coconut coir from another Victorian wholesaler that was prepared to send a relatively small quantity (3 blocks – about 25k) by mail and for fine organic compost I resorted to the local hardware warehouse. We had just had quite a load of composted topsoil delivered a few weeks ago, so it was pointless getting an additional load of organic compost. Not this time of the year, anyway. Our own compost wasn’t quite ready yet, nor fine enough.

Great was my surprise when the stuff arrived! The vermiculite we used in the course was like quite finely ground balsa-wood – OK, not exactly, but that’s the closest I can describe it. The stuff I received from the aquaponics supplier looked like lightweight granite chips – I don’t want to really mention it, but almost like Styrofoam. It’s a massive bag, so I’ll just have to trust their labelling that it’s organic. The coir we used in the course was nice and fluffy light damp soft “stuff”. I received a box containing heavy hard brown bricks! The road to life is rocky…

seed - mix

Vermiculite surprise

I consulted our ever present advisor, Google, how to expand compressed coir. You will be surprised how many YouTube videos there are out there about coir expansion. The simplest one for my purpose was this clip on Rob’s Channel, using two buckets, one with little holes in. I already had a bucket with a long cut in the bottom. One day the bottom will drop out! I’ve got no idea who was sawing what on a bucket – I suspect some of the tradies who did our paths way back when just left it here. Anyway it’s now got a few more holes in it – the bucket, that is, not the paths… The kids were very interested in the coir expansion part of the project – I couldn’t get them to stop playing with the slurry. Stir it up! It’s amazing how interested they become in something that looks like a messy experiment, but want nothing to do with anything that looks like routine work (like weeding).

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Nice and fluffy coir

So the next day was school holidays – the sun was shining and the weather sweet – and we were ready to make our own seeling mix. Again, the kids jumped in boots and all. One little bucket of these, two of those, three of the other – I hope I had the ratios correct! It’s fun mixing the light fluffy damp stuff. Next we carefully transplanted the struggling cuttings. Together we’ll fight this little struggle… Some had made no roots and were promptly replaced. Others had fine hair roots, but they also had pennyroyals from a previous seedling attempt overgrowing them – so they were carefully separated. The kids loved the fine work with the roots and especially giving some of the slightly suspect little cuttings a second chance. Some of the good “give it a fair go” Aussie philosophy must have rubbed off somewhere.

seed - mixing

Mixing seedling mix

So now we have a neatly organised greenhouse (OK let’s keep it neat this time round) with cuttings of blueberries, red currents, lavender, rosemary, pennyroyal, lemon verbena, lime verbena and boobialla all getting a fair go in the new seedling mix. I even found a brand new second-hand old remote little weather sensor I had brought over from South Africa in our original move, which has now been re-appropriated as a greenhouse temperature and humidity gauge, sending its measurements to a recording station in the study. So on those cold weather nights I don’t have to wonder how the plants in the greenhouse are doing anymore – how cool is that? Or rather, hopefully, how warm is that?

Greenhouse setup

You can fool some people sometime, but you can’t fool all the people all the time… any guess which artist was doing the rounds on my playlist?


About martin@muchmoremulch.blog (207 Articles)
My name is Martin Rennhackkamp, I now live happily in Lara, Victoria, Australia with my wife, two children and two dogs. My interests, apart from the obvious Organic, Biodynamic and Permaculture Gardening and Farming, include sustainable living, surfing, horse-riding, a wide variety of music, dancing, nature, birds, reading, Christianity and a few other things which I never get to...

3 Comments on Every time I plant a seed

  1. Hi Martin,

    Thanks for the informative article. Would you mind sharing the details of the suppliers for the above mentioned ingredients for your seedling mix?

    • Hi Glenn I got the vermiculite from A-Grade Hydroponics (Melbourne I think, I got it posted) and the coir from Sage Horticultural (also posted). The coir expands into real nice fluffy material. We’ll have to see how the vermiculite goes, but it’s light and airy, they claim it to be organic. Both very quick response times.

  2. That vermiculite looks more like perlite.

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