Learning how to make a great seed raising mix means you are giving your seedlings an excellent head start.
It also keeps costs down and is a great fundamental skill of edible gardening.
Recently up at the107 Rooftop Garden, that’s exactly what we were all there to learn how to do.
A dark threatening sky looked over the first monthly community gardening day.
Potential rain didn’t keep away this group of gardening enthusiasts though! With gloves and enthusiasm at the ready, it was time to get mixing.
Making your own seed raising mix is easy to do, and the results are so worth it.
First up for your mix you’ll need:
Compost– good stuff, use your own or buy the best you can get.
Coco coir– coco coir or coco peat is a more sustainable option than using peat moss.
Sand– helps with drainage, and doesn’t compact too much.
Worm castings– sift any stray worms out first.
Manure– we’ve used aged chicken manure here. Don’t use fresh stuff as it is too nutrient dense and will hurt the seedlings, and can also go mouldy. Small amounts of aged manure works a treat though.
You can make this up in smaller amounts, but bigger is a little easier though (done in an old bathtub here).
If you don’t think you need quite this amount, make it up with a bunch of friends and share it out!
A great excuse to get together, and talk all things gardening.
Add your ingredients in the following ratio:
- 2 parts compost
- 2 parts coco peat
- 1 part worm castings
- 1 part sand
- sprinkle of aged animal manure
And mix, and mix, and mix.
Next, you can either run it through a sieve to get all the bigger bits out if there are any (you don’t want chunky bits in there) or use as is.
Ideally you would now leave your seed raising mix for three days to get some of the moisture out and to let it all settle a bit (have it covered if you are doing this, to stop it drying out completely).
Here we got straight into it though, using the mix that had been sent through the sieve for the smaller seedling areas.
Fill your seedling tray, pots, empty toilet rolls or whatever it is you are using, and carefully level it all off.
Gently tamp the soil using two fingers – just lightly pressing down, you don’t want to compact the soil here at all. But you do want to eliminate air pockets.
Once this is done, top the containers up with as much of the seedling mix that is needed and again gently level it off.
Using a pen as a dibber, go down as far as you need to for the seeds that you are planting. Each seed has a different ideal depth, so check on the back of the packet for what your seeds need.
Drop in 2-3 seeds, and gently cover it over again with some of the seed raising mix.
Ideally, you should be gently misting your seedlings daily to keep them moist, until the first leaves appear.
Also, make sure you label what you have just planted as soon as it goes in! A chalk pen is super handy for this, if you’re working with black pots of seed trays
And now finally it’s time to watch your little seedlings grow!
More articles about growing good food at your place here…
If you would like to come and see the 107 Rooftop Garden for yourself, we’re running monthly community gardening days – a great morning of new skills, garden chores and free seedlings.
**This seed raising mix recipe is the secret sauce that all Allsun Farm seedlings are raised with. Thanks to Mike + Joyce for sharing their recipe!
Your guest writer today is Brydie Piaf – home baker, maker, blogger, photographer and wrangler of small people.
Thanks for the seed raising mix recipe! I have a question for you though ….I’m from QLD where seed raising was very simple. Here in Canberra, i either can’t get the seedlings to come up or they come up really long and spindly or they don’t go past the 2 leaf stage. Help! What am I doing wrong? I really want to use my heirloom varieties in my garden.
Sounds like light issues….. seedlings usually stretch to reach the sun. It can be hard in Canberra to give them enough light and still protect them from the heat / cold / drying out. In Queensland and Northern NSW everything grows so fast your seedlings are ready to be transplanted in no time….. everything takes so much longer in the cooler months down south, and extreme heat over 35C slows down all our vegetables as well… see the graph below. So if they take longer to grow and they are not getting enough light they use up all their nutrient… Read more »
Look forward to making this mix. Could you miss the worm castings if you don’t have them, or is there an alternative that could be used?
just up the compost if you don’t have worm castings 🙂
Hi,
Where do you source the sand from? I can only find tiny bags of propagating sand here in South Australia, are you able to point me in the direction of a bulk supplier or larger bags? Also what brand compost did you use? (Blue bag in photo?) I’ve been finding a lot of plastic in the brands I’ve been purchasing lately.
All and any help appreciated.
Helen
we’ve usually just sourced ‘sharp sand’ form a good landscape supplier? And for compost – geez that’s so variable. Usually we make our own or at a pinch get the best quality organic one we can find at the time… best of luck 🙂
Hi, can this seed raising mix be used indoors safely (with the manure and worm castings in there)? Or should I only use artificial potting mix indoors?
Jaya, do you mean for raising seeds inside? If so, yes. And if as a potting mix for indoor plants, you could use this mix as a base, and add a lot more sand/coir for drainage – commercial potting mixes are usually sterilised during production – and then become un-sterile, of course, because life happens – from my understanding, it’s this process (and its aftermath) that can lead to un-safe microbes moving in (legionella etc) because there isnt a balanced microbe population (like in good compost) to keep the nasty microbes in check – I’d much rather have compost that’s… Read more »
I have made one batch of this mix (minus worm castings because I had none, and the aged manure which I didn’t read about) and was amazed at the success rate of sprouting, but then things slowed down and I have the issue of long leggy seedlings with only 2 leaves. I tried watering with weak seaweed solution but nothing has really changed and although they are alive they are not progressing. Very frustrating. Now I am wondering if the manure and worm castings really are the secret. I don’t think light is the issue as they are in a… Read more »
So misting daily until 2 leaves stage, then what?! Stop misting? Transplant? My issue is they just stay young and small and doesn’t grow to same stage as those found at nursery and I have no idea what I did wrong 🙁
Giday there Nick and Kirsten,
I was wondering if there could be a local substitute for cocopeat (I live in Tas), or if you have found a way of getting it without packaging? perhaps used coffee grounds or something along the lines? Cheers!
Hi! Thanks so much for sharing this. I’ve tried using compost and/or work castings in the past in DIY seed raising mix, and my issue has been that pumpkins, tomatoes, and other seedlings that tend to emerge from compost can compete with the seeds I’ve planted. Anyone else have this issue?
I had this problem too but I now spread my compost in a 5cm layer over a tarp and keep it moist for say 2-3 weeks. During that time seeds will germinate and you can get rid of them by pulling them out.
Hi, I was ready to buy a bag of seed raising mix to start my spring seeds growing. Then I found your diy seed raising mix recipe. I realise I already have everything I need to use in my shed. I made compost over the last 4 months, my worms have been gobbling for that long too. The sand is at the bottom of my seaweed container. The manure I collected, by chance, from a cattle holding yard. Yippee!! Thanks.
so good!
That all makes beautiful sense. Thanks for putting together such a great article. I’ll be giving it a go this weekend. will show you the results