Homemade sowing / potting mixes?

[gregorach]

There's always plenty of talk about compost making, but I was down at the allotment filling module trays today and it occurred to me that's there's not nearly enough talk about how to take your lovely garden compost and turn it into a decent general-purpose sowing / potting mix... I'm trying to minimise the amount of fertility I import onto my plot, so I'm trying to do without buying potting compost. (It's a right pain in the backside to transport by shanks' pony, for one thing...) I've tried using my compost straight and whilst it's OK for growing established, hungry plants, I've not really been happy with it for seed sowing or early potting up. I've also tried a few variations involving various additives, but still not really got what I'm looking for... I think I'm getting closer with my latest recipe (formulated today), which is 4 parts sieved garden compost, 4 parts sieved soil (I'm blessed with nice loamy soil), 1 part vermiculite and 1 part rock dust. It's starting to feel a bit closer to a proper potting mix, but it'll be a while before I find out how it performs. Maybe needs some coir or something....

So, what does everybody use? I'm sure there must be someone on here who's tried everything...

[Dave]

I've always had good experiences with leaf mould - straight and mixed, the older the better. Always worth having a supply of it.

[grahamhobbs]

Yes leaf mould, and sharp sand perhaps in lieu of vermiculite.

[Harasimow]

Funny I've just been sieving my first batch of homemade compost today, and I thought to myself this is so good it could be used as potting compost. Think I would need to mix it with somthing else to make it more suitable though_> then this thread poped up!! will be keeping an eye on this!

Regarding leaf mould mines only one year old so none untill next year at the earliest. Do You peeps have more than one leaf mould cage?

[grahamhobbs]

Should have but don't, just take from the bottom

[contadina]

There's some great ideas for potting mixes at http://subsistencepatternfoodgarden.blogspot.com/. Mike always grows the most amazing veg, so I reckon he knows what he's talking about.

[Millymollymandy]

Regarding leaf mould mines only one year old so none untill next year at the earliest. Do You peeps have more than one leaf mould cage?

We have about 5 but basically we have one for this last winter's leaves, one for the previous winter's leaves (turned once) and then one for the current (being used) leaf mould. The two year old + stuff is like potting compost. So as bin no 3 gets emptied then bin no. 2 gets turned once into it and so on. The other two bins are just spares but go through the same turning process.

I use our leaf mould and very well rotted compost for my tomatoes in huge pots but would never use it for seeds as they are just full of weed seeds.

[gregorach]

Sounds like I need some bins for leaf mould then... We get plenty (and then some) delivered to the sire every autumn by the council, my problem's just finding somewhere to stash it 'til it rots down properly.

That's an interesting looking blog Contadina, thanks.

I do have a bit of a problem with weed seeds in my compost... Hoping this (or rather, last) year's will be better.

[oldjerry]

I've always just dug a hole and filled it with leaves then covered it with soil and uncovered a few months later.Or you could just fill up black bags stab with fork and pile them up.You know this anyhow.
The sowing mix sounds good,praps abit of grit(a la JI No1 ) as the nbetter the drainage the less the chance of damping off.
Someone with your ingenuity should be able to work out a non-chemical way of sterilizing that loam.Somewhere there must be a photo or two of the old heat sterilizing contraptions to give you some ideas.(there's a good photo in The Small holder Encyclopedia circa 1950,sorry my copy's in a packing case somewhere,and I wouldn't have a clue how to down load it anyhow but a decent library might find it)Best Wishes.

[Dave]

I've been spreading out leafmould, letting it grow a flush of weeds, weeding it, then doing the same again. So far so good, the weed problem is minimal.
Quite lucky to have a large formal garden near me where I know the gardeners really well - they have a big pile of ten year old leaf mould and they're happy for people to take small amounts for free or larger amounts at a small cost.

Some sterilise loam in an oven or if you can remove all the stones Garden Organic advise using a microwave.

[gregorach]

I've always just dug a hole and filled it with leaves then covered it with soil and uncovered a few months later.Or you could just fill up black bags stab with fork and pile them up.You know this anyhow.
The sowing mix sounds good,praps abit of grit(a la JI No1 ) as the nbetter the drainage the less the chance of damping off.
Someone with your ingenuity should be able to work out a non-chemical way of sterilizing that loam.Somewhere there must be a photo or two of the old heat sterilizing contraptions to give you some ideas.(there's a good photo in The Small holder Encyclopedia circa 1950,sorry my copy's in a packing case somewhere,and I wouldn't have a clue how to down load it anyhow but a decent library might find it)Best Wishes.

I'm on an allotment - strictly limited space, all of which is currently in use (and I really mean all of it!), and no electricity. Soil sterilisation through heat is incredibly energy intensive, and I'd really rather not go down that route. I'd be better off getting bulk deliveries of municipal compost - they do really good high-temperature composting in huge volumes. Very efficient.

Some sterilise loam in an oven or if you can remove all the stones Garden Organic advise using a microwave.

There's absolutely no way I'm backpacking all my potting media home, sticking it in the oven, and then backpacking it all back again... I'm trying to get away from having to backpack it in in the first place.

[Dave]

There's absolutely no way I'm backpacking all my potting media home, sticking it in the oven, and then backpacking it all back again... I'm trying to get away from having to backpack it in in the first place.

Fair enough! Even with a bike trailer its difficult enough. I would always start things off at home and then carry the seedlings to the allotment, it meant lots of trips and there were casualties along the way but it kind of worked.

[gregorach]

My flat is even smaller and more overcrowded than my allotment, and it's entirely north-facing, whereas I have a 12' x 8' greenhouse on the plot.

[fifi folle]

I keep toying with the idea of sterilising my compost with my wallpaper steam stripper, but that doesn't solve your problem though, Dunc!
Here's a thread from another forum on this topic with different suggestions...http://forum.downsizer.net/viewtopic.php?t=2677&start=0

[oldjerry]

I knew you were on an allotment,what I had in mind was something like an oil drum brazier,fuelled by free pallets,and warming your frozen mits in the middle of a northern winter...