[habanerohead]

It's time to empty the worm bin again and I was thinking about mixing it with coir to make potting compost. The worm compost looks very much like nice soil, and it's been "made" entirely from kitchen waste so it should be packed with nutrients. I also put pulverised eggshells  in whenever the worms show signs of wanting to leg it.

Will it be enough to just mix it with the coconut fibre, or do I need to add other stuff to it.

Tips and recipes would be appreciated.

Cheers.

[Yorkie]

What do you plan to use it for?  Different stages of plant growth need different nutrients / sterility etc.

[habanerohead]

Mostly starting stuff off before I take it to the lottie, so I guess the the equivalents to JI seed and cutting, #1 and #2.

[Yorkie]

I would not advise using it for seeds.  It will not be sterile.

It would probably be OK for interim potting up - you could add some FBB if you wanted and plants were going to be in there for more than a couple of weeks.

It will not be substantial enough on its own I would have thought as JI 2, which is recommended for more permanent type planting.

[habanerohead]

FBB?

OK, what would you put in it to make it into a decent potting compost?

[mumofstig]

FBB - Fish, blood and bone 

[habanerohead]

Ta.

I tried a Google search on FBB and got "Female Body Builders" - that was quite an interesting little excursion!

[goodtogrow]

If the addition of coir is intended to improve the structure of the compost, and therefore aeration, you could achieve the same by adding sharp sand/horticultural grit.

I use garden compost cut 50/50 with pea shingle for all my transplants.  Plus a bit of lime.  If you use big enough pots/modules (I use 75mm square pots) there's enough nutrition in that volume to sustain the transplant without adding anything else.

Water holding is provided by the organic matter but as the transplant matures my own 'chunky' mix, highly aerated, tends not to hold enough.  So the pots are stood on capillary matting to provide bottom watering.  Personally, I'd rather have an 'open' mix than one which slumps, cos I think the plant would prefer that too...

Best wishes

[habanerohead]

I mainly want to make my own potting compost because I haven't found any that I really rate - they're quite expensive, a hassle to get home, and besides, I've got loads of worm product that I want to use and I thought potting compost would be a good use for it.
The worm compost looks like really nice soil, but I've read that it's too rich to use straight, so I'd need to bulk it out with something, and coir sounds like it'll do the job. It's eco-friendly and you can get it in very lightweight bricks that expand an amazing amount when they're hydrated, so it's very convenient to store until needed (another advantage over bagged composts).
I could just experiment I guess, but I'd hoped that someone on this forum might have some useful tips or whatever.
There is someone selling coir and cast potting compost, but he doesn't give any recipes - why would you if you're selling the stuff?

[solway cropper]

I've been making my own potting compost for years out of stuff from the daleks mixed with sterilized loam and the contents of cheap grow-bags. Nutrients are added depending on the type of crop to be grown.

I don't use it for seeds for the reason previously outlined but it works fine for most things.

[Kristen]

Certainly not recommending this, per se, but I reuse my seed sowing compost from year to year.  I tip the seed trays, after pricking out, into a bag and following year put in a pyrex bowl with water in the base (i.e. add water then add compost, not attempting to mix the two), cover with cling film and microwave for 5 minutes at least.  It takes ages to cool, so the heat will have an effect over a prolonged period of time.

If I get anything diseased I discard the soil, but its a rare event - I have had one occasion of damping off, that I can remember, since we have been here - which is 7 years now

Whilst in confession mode I don't wash my pots either ...

[Yorkie]

Whilst in confession mode I don't wash my pots either ...

 

(Neither do I, much) 

[barley]

I make my own compost - have done for years

I rot all waste down from veg plot garden and chooks for 3 years - ( I have 3 heaps rotating )

I am lucky to live in a rural location and have a supply of free mole hill top soil in fields around me - I collect a bucket when walking the dogs but top soil from the veg plot should be ok

mix 50 % of mole hill to 50 % compost heap in a large bucket then sieve with a garden sieve and the course unrotted stuff ( technical term unknown  ) can go back on heap to rot some more

its just like wot you get in a bag from DIY shops but absolutely free

I've never had any failures with germination etc. so I guess I could say its ok 

[goodtogrow]

Picking up on the op's last post I'd like to suggest that a combination of coir and worm compost does not, necessarily, make for an optimum potting medium, and that such a mix is no better than other proprietary mixes which we've all found wanting.

I'd like to big up the need for aeration, and my experience tells me something inert like sand/grit/gravel does the job.  Coir's water holding will exclude air when it expands, so in combination with worm compost an areated mix is unlikely, without very careful, lean, water control.

A combination of coir/worm compost/grit in equal volumes sounds good to me. Barley's mix sounds delicious, but I'd still add some grit to that too.

Whatever the mix, and particularly when using Multi-purpose compost, I'd argue against top watering in favour of bottom watering, delivered through capillary matting.

Best wishes to compost mixers everywhere.

Tom

[mumofstig]

A very old post with advice for mixing compost, suggests the need for grit in the mix
http://chat.allotment-garden.org/index.php?topic=3541.msg39598#msg39598