Making john innes type compost

Does anyone have a good recipes for making good john innes type composts? I have already tried making some by mixing:

X 2 parts peat type B&Q compost
X 1 part topsoil - topsoil (loam?) I live in an area of fertile clay type soil
X 2 washed sharpsand.

Any good with what I have done? tests so far growing tomatoes/peppers in it seem to be going well although it does drain quickly.

 

Trig - what you have done is absolutely right. The actual recipes are here http://www.gardeningdata.co.uk/soil/john_innes/john_innes.php But I don't think you have to be exact. Plants grow in anything from pure soil to pure compost. As I see it the principle is to add sharp sand for drainage and garden soil as well.

The different mixes have different levels of feed added. But I don't think that matters if you are feeding your plants regularly.

I use that sort of mix for flowering plants in pots. Traditionally tomato growers may use a bit more peat. I am sure you will get comments from veg growers.

 

Your spot on, aside from an extra part peat and one less sand if growing veg.

If im working in a garden were I make leafmould then I usuly add a proportion of this aswell.

 

How do you sterilise it Pro?

I've got a heap of nice topsoil here, covered with tarpaulin, but it came from an area with lots of mares tails, and I wondered if I could hire a sterilizer machine, or somesuch, to sterilize it such that it will kill the weeds?

 

Kristen, Generally I buy the top soil in pree bagged and sterilized, same for when I make lawn top dressing overall if making a lot up it does still work out cheaper plus you can vary the percentadges acording to use.

The leaf mould I know is virtually weed free and Ive never had a problem.

 

"The leaf mould I know is virtually weed free"

I think mine would be full of Sycamore "helicopters" :D

Any knowledge of commercial sterilizers that I could perhaps hire?