I started blending my own seed raising mix because at the school garden we were going through so much of the expensive stuff.
My old formula was:
I buy in the compost -- el cheapo: like Richgro at $3.95.
I have a load of river sand that I rely on.
I've now added composted cow manure -- also at $3.95/bag (Fine Farms).LINK.
I can get plenty of manure from local farms but I didn't want to start using it raw so for now I buy the bags.
If it works I'm planning to go to the local source.I prefer working with horse manure but cow has fewer grass seeds.
What got me thinking about manure usage was this video on making 'the perfect soil' from India. I'm not the least bit religious so the Verdic auspicing doesn't register with me. However, the video is really good and it ticks a lot of boxes from my perspective.
It is also disparaging of all the effort you'd need to invest in making your own compost.
Given my location, I've always wanted to embrace a routine partnering local livestock, as on these small hobby farms, dung is a management problem and there is a niche sharing the stuff from farm gates.
Mind you how I can get compost and composted cow manure for $3.95 per bag amazes me.You cannot be sure of its provenance but it is all feed for soil and microbiology.
And I'm no purist.
However,Richgro products may come all the way from Western Australia(!) but...
"Richgro is proud to be an ISO 9001Quality endorsed company. We supply quality certified products and hold Australian Standard 4454 for our Composts, Soil Conditioners, and Mulches, and Australian Standard AS3743 for our packaged Potting Mixes. We also have Australian Certified Organic certification on a number of fertilisers and soil conditioners and water saving certification on our soil wetters and mulches."
I should, nonetheless, point out that the industry has recently been exposed in a terrible way as here in Brisbane, NuGrow has been adding toxic fire fighting foam to its composts (LINK).
The video also has a great discussion on desiccated grass extras. Indeed I think my soil is now so earthworm rich because those many loads of grass clippings I've thrown at it now feeds the multitude.
I also now use simply brewed weed teas when seed raising but I cannot as yet make a ruling on their efficacy.
For punters of the activity, so far I've resisted the option of adding Perlite to my mix because it is so expensive for so little. As it is Osmocote seed raising mixes are 3 times the cost of my DIY blend.
Dave, do you just start seeds in this or keep seedlings in this until they are big enough to go into the garden?
Until they are big enough to go into the garden.
Perlite is not expensive if you can buy in bulk need to get a cubic metre bulk bag need to find a company that uses or contact the manufacture for a supplier. would not buy commercial compost they put toxic waste in the compost like sandblasting sand and landfill leachate. they are investigating where firefighting contaminated soil went from air force base here in SE Queensland may have been sent to a composting facility.
Sawdust can be used in the seed raising mixture but needs to be correct type and not from timber that has chemicals .
There used to be 100L bags of both Perlite and Vermiculite available from the now-defunct produce store at Rothwell. I've not looked into who might stock it now although the successors to that shop may do so. I still use Vermiculite to make up a new mix, I found Perlite was very dusty and not using a mask, figured it could be a health hazard.
If you use commercial compost - and I do - go for the local product from the Gold Coast. There is never enough of your own compost.
If push comes to shove I'll add cat litter/vermiculite...But the sand should suffice and I have that in quantity.
So the current working formula is:
Since I've spent the last two days mixing this up and planting my seeds -- I'll soon find out whether it works.
Just went outside and bloody big Ibis was walking over my seed pots as though they were stepping stones!