Homemade Seed Raising Mix

Knowing how to make your own seed raising mix is, I reckon, an essential skill. It means that no matter what, you can always sow seed and in this way, keep your food garden productive. Seeds are more versatile than you think and adpt to a wide variety of ingredients. Look about and see where they pop up – in the darnedest of places, aye.

That being said, its important to note that I am not on a mission to do every single little thing myself. There are times when bought seed raising mix is a godsend. Here’s how to choose bought stuff, well:

  • Go organic, or at the least, choose a mix without fungicides or artificial fert or peat.
  • Use your sense of smell. If the mix is sour, or in anyway off … ewww, walk on by. If its smells bad, it is bad.
  • Give the bag a little squeeze and if it feels wet and clumpy, forget it, opt for a looser brew.
  • Choose bags that are stored undercover/ in the shade. I mean, really. Can you think of a single thing that benefits from being sealed in plastic and sat in the sun? No. Me neither.

If there’s no pre-mix to your liking, buy the separate components instead or read on, gardener – perhaps you have all the ingredients at home!

My very flexible recipe

homemade potting mix

There are 100’s of tried and true “best” seed raising mix recipes out there. From this, you can deduce that its very flexible. Use whatever OM (organic matter) you have at hand, its like making a stirfry – cobble together all the bits and pieces!

a handful of rotten manure for seed raising mix
Leave your manure until its properly broken down before using it in seed raising mixes.

Seed raising mix has more grit than potting mix, otherwise they’re the same recipe.

My very flexible brew is as follows
+ a third is the food – compost or well rotted manure or vermicastings
+ a third is the drainage – river sand, really well rotten sawdust or propagating sand
+ a third is the moisture retention – leaf mold, vermicastings or the yummy stuff beneath mulch, under trees. Something peat-y, but not peat, please lets stop the mining.

a handful of leaf mold
Leaf mold is deliciously peaty – perfect for seed raising mixes

You can also go 50/50 homemade compost + grit, or one of my often used duos – vermicastings + grit. Bought compost is super concentrated, so use less.

Make enough for the job at hand – there’s no need to make loads at any one time. If you are a regular OM collector, then you will always have ingredients available and as you can see – its a super quick job!

testing potting mix by squeezing it in my hand
Give your mix a squeeze to feel if its loose enough

Mix together your chosen ingredients. Test it, by squeezing a handful. It should be quite loose with a small amount of stick. Your seeds will soon show you if they are happy or not, and in this way you’ll get better and better at your homemade brews.

PS – I don’t sieve the bits out! Nature doesn’t and all her seeds grow perfectly well, as do mine.


  1. Thanks Kath. I have almost got it sorted. And now I know that I don’t have to sieve it, will make it so much easier. What was I thinking 🤔…
    I’ve got the pesky birds helping with my compost too, found them digging out underneath the bins, pulling out the stuff that’s ready to use. Cool hey 😁

  2. Hi Kath

    Love your blogs. We have an abundance of sphagnum moss and gets lots of sand delivered to our gate courtesy of a West Coast river. Would I be right in thinking that I can do a mix of sphagnum moss, river sand, and compost with well rotted chicken poo, to make a lovely seed raising mix?


    • Yes! the west coast strikes again, so well resourced! Just be aware of overdoing the food third in this scenario…. keep the ratio’s – third moss, third sand, third compost + poop. Bet your seedlings go off.