Green Johanna – Review

On the many benefits of my new hot composter ‘Green Johanna’. If you’d like to know my top secret tip on how to get yours at a fraction of the advertised price, make sure to read to the end!

I mentioned in a previous post that one of my five main allotment goals this year is to upgrade my composting situation.

At the start of the year all of my compostable allotment waste was going into an ancient wooden composter I inherited with the allotment. It had done a perfectly fine job of holding my compostable garden waste, but this winter was set to be its last. Patches of it had turned green and it was quite literally crumbling away! Having recently discovered the vast benefits of the no-dig system and consequently having become slightly evangelical about compost, I spent a long time investigating what options I had to replace it, focusing particularly on composters which would produce top quality compost quickly.

I settled on the Green Johanna due to its glowing reviews, including Gardeners’ World Star Buy! Green Johanna comes from Great Green Systems who also make a number of other useful products including food waste digesters and water butts (tell me it’s not just me chuckling at the word butts!).


Green Johanna arrived flatpacked in a plain cardboard box with minimal plastic packaging. Assembly took minutes and was so simple that it didn’t come with instructions – simply stack the hooped pieces, line up the letters A >< A, B >< B and so on, and screw together.

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The main thing to remember with composting is to LAYER. You want to layer garden waste (carbon) and grass clippings/food waste (nitrogen) in a ratio of one part nitrogen to two parts carbon. Green Johanna comes with a booklet which explains this concept clearly and provides more examples of what you can compost if you’re unsure.

The second very important thing to remember is to STIR your compost. Green Johanna comes with a sturdy wooden compost stirrer just for this purpose with a well-designed folding head for catching up all of the bits at the bottom! Stir a little each time you add any material and more vigorously once a month to speed the process on. You should be rewarded with the best ‘black gold’ around and best of all – it’s totally free!

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I chose Green Johanna for the promise of speedy, high-quality homemade compost but I was pleasantly surprised by the wealth of other useful features, such as the enormous 330 litre capacity and the two handy hatches for accessing compost. It’s also a huge bonus for me that Johanna can take cooked food (you can’t usually put cooked food in a composter but Johanna is fully rat proof). As someone who hates food waste I rarely have cooked food that spoils, but on the odd occasion where it does all go wrong I can rest easy, knowing that my food waste isn’t really waste at all but future compost!

As I’ve only just installed Johanna I can’t yet comment on the compost itself – but I’ll be sure to keep you updated on progress as this year goes by! I really can’t wait to sustainably produce trugfuls of the best nutrients for my garden and I hope you will consider getting your own Johanna to help you!


If you’d like to get your own Green Johanna hot composter:


It is worth noting that many local councils offer significant subsidies so do check whether this includes yours by entering your postcode into the box on this page!

Happy composting!

Bryony x

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5 thoughts on “Green Johanna – Review

  1. Hi Bryony, I have just received a Green Johanna and keen to start using it. The guy in the useful video on the Great Green Systems website says he uses cardboard – from the Johanna delivery box and other cardboard products. The Johanna handbook does not mention cardbord in any form apart from egg boxes. Have you use cardboard successfully?
    Also, like you we hardly have any cooked food waste – plenty of uncooked veg peelings etc – so Im a bit reluctant to rely on too much grass cuttings to provide nitrogen. What do you layer your raw veg peelings etc with?
    Many thanks


    1. Hi David! I haven’t used cardboard I’m afraid. I have used shredded paper in the past when the Johanna looked too wet (not sure what the manual says about that!). I layer at the moment with food waste and allotment weeds and grass clippings. I’m also adding plenty of chicken manure (again, not sure what the recommendation is there!). I’ve not stuck too closely to the layering system but I have kept it well mixed as I’ve found this helps to break it down faster.


  2. How did you get on with this composter? I am considering purchasing a hot composter and was interested to see your thoughts after using this one for a few months.


  3. Hello ,I don’t know if it’s just me or if perhaps everybody else experiencing problems with your blog. It appears as if some of the written text on your content are running off the screen. Can someone else please comment and let me know if this is happening to them as well? This might be a problem with my web browser because I’ve had this happen before. thanks


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