John Innes

[Loripep]

Hello all;

I was wondering if someone can tell me of a Canadian brand of potting soil which is equivalent to John Innes 1 or 2. Is there such a beast?

Lori

[Maggi Young]

Hi, Lori, great to have you back in the new forum, we missed you!
I'm sure those Canadians out there will have a good suggestion for you for your John Innes mix, Canuck style!

[David Nicholson]

Hello all;

I was wondering if someone can tell me of a Canadian brand of potting soil which is equivalent to John Innes 1 or 2. Is there such a beast?

Lori

Hi Lori, to help you in your quest the following is the recipe for making John Innes Compost-it is so called because the formula was devised by the John Innes Institute (in the 1930's) a horticultural and agricultural research body.

The basic formula is:
7 parts by bulk of sterilised loam (loam, as you will no doubt be aware is made by stacking turves for say 12 months and then passing the residue through a fine sieve) although a reasonably fine garden soil would just as well apart from it containing lots of weed seeds!!
2 parts of course washed sand
3 parts of moist moss peat.

To each bushel of this mix (the quantity that will fit into a box 22inches x 10 inches x 10 inches without compacting) 4 ounces of a mix of 2 parts superphosphate, 2 parts hoof and horn and 1 part sulphate of pottash an three quarters of an ounce of ground limestone or chalk.

All of that would give you a John Innes No 1 mix. For a No. 2 add twice as much fertiliser, and for a No. 3 three times as much fertiliser.

You probably see now how lucky we are in the Uk that we able to buy it ready mixed. The quality of it does vary a lot with some manufactures lowering the loam content and replacing it with more sand and peat.

Hope this helps a bit.

[Lesley Cox]

It does indeed help David as I was wondering too as there's nothing of the kind here. I think I have the recipe somewhere, maybe an old Lawrence D. Hills book but I'm too lazy to go looking at present.

I firmly believe that at least a SMALL quantity of basic loam or garden soil is very beneficial in virtually all potting mixes. There are pathogens and other greeblies (you note my scientific turn of mind?) that peat or bark based mixes are lacking and which help keep harmful fungi etc at bay. I always add a little even if it's only about 1/20th

[Maggi Young]

I firmly believe that at least a SMALL quantity of basic loam or garden soil is very beneficial in virtually all potting mixes. There are pathogens and other greeblies (you note my scientific turn of mind?) that peat or bark based mixes are lacking and which help keep harmful fungi etc at bay.

I'm with you there, Lesley, that's why I am doubtful about sterilising composts.... too many good guys getting frazzled with the baddies! I'm sure the baddies are better at re-colonizing than the goodies, too.
not saying it is never necessary to  sterilise a growing medium, but it never happens here. Not after I discovered how bloody awful soil smells after Ian blitzed it in the microwave, anyhow!

[David Nicholson]

I firmly believe that at least a SMALL quantity of basic loam or garden soil is very beneficial in virtually all potting mixes. There are pathogens and other greeblies (you note my scientific turn of mind?) that peat or bark based mixes are lacking and which help keep harmful fungi etc at bay.

I'm with you there, Lesley, that's why I am doubtful about sterilising composts.... too many good guys getting frazzled with the baddies! I'm sure the baddies are better at re-colonizing than the goodies, too.
not saying it is never necessary to  sterilise a growing medium, but it never happens here. Not after I discovered how bloody awful soil smells after Ian blitzed it in the microwave, anyhow!

Maggi I agree. Quite honestly I can't see manufacturers of JI type composts spending money on sterilising loam, they would much rather look for ways of putting in the least possible amount of loam they can get away with. One of my Auricula growing friends gave me a little tip to test the quality of loam based compost and I will pass it on here. Take one clean jam jar with lid-take one handful of compost and add it to jam jar. Top up jam jar with cold water add lid and shake. Allow to settle, loam sinks, humus stays in suspension. It's a little rough and ready but if you try it you will see if you have any of either (Loam and humus that is) I'm rambling again, must be getting tired!

[Lesley Cox]

Sounds like an interesting way to revert to one's childhood David. I seem to remember having different things in jam jars to my mother's horror. She was never sure what was in the fridge that could crawl out, or maybe get added to a casserole by mistake.

Yeah Maggi, that smell sure is horrible!

[illingworth]

Hi Lori,

We were waiting for you to re emerge and you did so on the first day of spring! Perfect timing.

We use Sunshine Jiffy 4 mix to which Sharon adds perlite and chick grit number 2 (granite chips), and sometimes a bit of sand or some leaf mould, depending on what is being potted up.  We have also added Turface to the mix but have cut it out as we think it promotes the growth of liverworts. This is just used as a seed germination mix or for growing on prior to establishing in the garden - not for long term pot culture - which we don't generally do.

-Rob
http://www.flickr.com/photos/illingworth/

[Loripep]

Thanks everyone;

Think I will try the mix recommended by Rob. He and his wife Sharon have a beautiful garden and kindly toured me through it last summer. All in a cold Canadian zone 3 or 4!

Love the pictures of the garden Rob.

Lori

[Rodger Whitlock]

I was wondering if someone can tell me of a Canadian brand of potting soil which is equivalent to John Innes 1 or 2. Is there such a beast?

The John Innes mixes are characterized by:

1. texture, including content of organic matter, clay fraction, and minerals (sand)
2. pH
3. nutrient levels

I mix an approximation to the JI potting compost as follows:

Ingredient	Quantity	Comment
Island's Finest Top Soil	30 liters	from Canadian Tire
perlite	10 liters	horticultural grade! Perlite sold for building insulation may contain fluorides toxic to plants
4-6-8 organic veg. fertilizer	144 g	from Canadian Tire
Lime		lime, not dolomite; amount depends of pH of bagged soil
pH = 4	203 g
pH = 4.5	168 g
pH = 5	135 g
fritted trace elements	7 g

You should be able to buy these ingredients locally, except the "top soil." It's a local product here on Vancouver Island, dredged from an old lake bed and bagged without treatment. In devising this recipe I made the assumption that it contained silt and peaty organic matter in about the right proportion to match the JI formula for rotted turves plus peatmoss. It contains coarse debris (twigs, leaves, etc) and is bagged very wet, so I spread it out to dry and when dry screen it to remove the debris.

The amount of lime is calculated to give pH 6.5 in the finished mix.

In practice, I find that the amount of perlite is a little low and the mix is a little too dense and airless for many plants, so I mix 1 part perlite to 2 parts of this soil mix when potting up many things. For seeds, I mix equal volumes to give a light, airy mix that many seeds enjoy.

The moral of this somewhat long-winded description is that you can probably find suitable ingredients to make a rough approximation to the JI compost. What I mix may not be ideal, but at least I know what's in it. Friends to whom I've given some for potting their summer annuals say it works far better than any commercial potting mix made for the same purpose.

At one time I used granite chicken grit instead of perlite, but the grit became too costly, and perlite is very cheap when you buy a 100+ liter bag.

I'm sure members of the SRGC elsewhere can find similarly suitable make-do ingredients with which to mix a mock JI compost. As I said, at least when you do that, you know what you have in your hands!

Hope this helps!

Postscript: I see I failed to explain why I use the "Island's Finest Top Soil". Very simply, it's extremely cheap, often available for $2 (CDN) for a 30 liter bag. Also, though it contains natural debris and is ridiculously acid, it contains no additives of any sort, so I am not putting myself at the mercy of some stupid person with a bag of fertilizer.

[Maggi Young]

Good idea, Rodger, with so many commercial mixes nowadays there can be all sorts of odd nasties in 'em!
Have heard lots of complaints from unhappy gardeners who have been let down by commercial mixes.... much better to make your own as you suggest.