Wednesday, March 9

The Green Johanna

Thanks to my voluntary work with York Rotters, I recently took delivery of a Green Johanna compost bin to try out.  The GJ is not your standard garden composter - it is a hot composter, and also designed to be rodent-resistant*, meaning that it is suitable for composting all types of food and garden waste - yes, including cooked food and meat and fish.  Having struggled with Bokashi composting in the past, but not wanting to throw our occasional cooked leftovers or chicken carcases in the bin (all else aside, with fortnightly collections the bin becomes horribly smelly) this sounded perfect.

The instructions weren't terribly clear - but once I got the box open it was a simple enough process to put the thing together, just a matter of clearing a suitable patch of ground - the instructions specify that the composter should be placed directly onto soil, in a shady spot so that it doesn't overheat in summer (it was designed for year-round use in Sweden, so the average British winter shouldn't trouble it) then stacking the segments in the correct order.

It even comes with a stirring device!

With this little area between my bird feeders and bike shed cleared (nothing grows there anyway, it's too shady for most plants) I picked a spot for the base-plate and started stacking.  The Green Johanna goes together a bit like Lego, and screws are provided to make it all a bit more permanent.  Unfortunately, on mine none of the screw-holes quite matched up so I didn't bother - perhaps when I've a little more time on my hands I'll drill some new pilot-holes and fasten it all together.

It's pretty imposing when it's built up, so I'm glad I tucked it away behind the wall!

The last step of setting up is to prepare the Green Johanna for your kitchen and garden waste.  In order for air to circulate well the bottom 10 to 20cm needs to be filled with twiggy material - our hard winter has provided well for this, and I topped it off with my dried out Valentine's bouquet!  The next layer needs to be green garden waste - the instructions suggest grass-clippings, but as we've yet to mow the lawn this year I made do with as many weeds as I could pull up from the garden.  A third layer, of garden soil or well-rotted compost, is needed to add the micro-organisms that will do all the hard work for you, then you're ready to add your first kitchen scraps or garden waste proper!

Super-simple, and now I need never throw food in the bin again!

* The manufacturers claim that it is 100% rodent-proof, I am naturally cynical of such claims, having seen what rats can chew through if they've a mind to!


  1. Does it work for perennial weeds? I have a standard composter and I don't throw ground elder in there as it would just go mental

  2. Gareth - It should get hot enough to kill weeds, but if you want be sure (or want to put them in your normal composter) you just need to make sure they're properly dead first! The easiest way to do that is to stick them in a covered bucket of water or a black bag until they've rotted down. Once they've gone sludgy you can stick them on the compost as usual. It's worth doing this as perennial weeds' deep root systems draw up lots of minerals from deep in the soil, which you might as well take advantage of!

  3. Hi Melanie. I am glad you have now received it. On the Green Johanna there should be arrows, which look a bit like drips of gloss paint, and if these are lined up then the pilot holes should all line up correctly. City of York Council and North Yorkshire County Council are subsidising Green Johannas until March 31st so anyone living in these areas and are wanting one should order before the end of March and are available from They are currently £59 RRP over £100. Regards Catherine York Rotters