Free Banana Peel Fertiliser

If you've been following my blog from the beginning you'll know that my mission is to turn my overgrown and neglected suburban garden into a productive kitchen garden, on a budget, without upsetting Mother Nature too much. I love this garden hack because it combines all of those things and can mostly be done from the comfort of my favourite chair.  What can I say, I love lazy gardening.

The other day on twitter I asked people if they could tell what I'm making in this picture

At time of writing I've had no correct guesses, but I'll grant you it is a tricky one.  This is banana peel fertiliser, and that's what I'll be talking you through making today.

Being gentle with nature means lots of different things. To me it means not spraying my garden with insecticides and trying to garden in a way that welcomes nature in to help while making space for it. But it also means trying to reduce my waste, reuse what I can, and trying to consume more consciously. I love making this banana peel fertiliser because it makes my plants grow beautifully, but it also reuses kitchen scraps and is quite therapeutic to make.

Banana skins are great to use in the garden because they are full of soil enriching nutrients. I'll often bury banana skin in the soil below a perennial tree or shrub, so I know it'll be getting a feed a few years down the line when the skin breaks down. But they take a long time to start rotting down, so if you want to use banana skins to feed annual plants, or plants in pots, or older plants who don't like their roots disturbed, you'll need to break the banana skins down for the plants first.

I'll be adding this to my big raised bed, but you can use it as a top dressing for potted plants whose soil is getting tired, or as a mulch for hungrier plants like potatoes, or to add to your home made compost.

You will need:

• Banana skins (chuck them in a bag in the freezer until you've got enough to justify doing it if you don't have 4 children all eating bananas at the same time)
• A baking tray
• Use of an oven
• A pestle and mortar or, if you haven't got one, you can makeshift one out of a big mug and a rolling pin 

Method

Spread your banana skins out on a baking tray and pop them in the oven on a low-medium heat until they are blackened and crispy but not burnt and smokey. The exact time needed will vary depending on the moisture content of your banana skins, but when I did it earlier today it took around 45mins to an hour with the oven on 120°

When the skins are crispy and black (and don't feel damp, squidgy, or floppy at all)  take them out of the oven and let them cool until you're able to comfortably handle them.

Then comes the threaputic/on the armchair part. Break the banana skins into your pestle and mortar/mug and rolling pin arrangement and pummel at it until the banana skin is ground into a beautifully rich, woody compost type substance:

And that's it. I like to set an intention while I do the grinding (witch talk for "tell the fertiliser what it's for") but that part is entirely optional.

Time spent:

About an hour cooking and then about half an hour grinding.

Total cost:

Free, but for the electricity to heat the oven.


It's now ready to add to your plants - just sprinkle it around them, the rain and worms will take it to the roots for you. Or add it to your compost bin, or lasagna bed, or anywhere else the plants could use a feed.

In terms of quantities - 3 banana skins yielded me a good handful of fertiliser - plenty for a houseplant or two since a little goes a long way. I'm going to be wanting a lot more than that to contribute to filling my big bed for free though. I could save it in one of my hoarded coffee jars (yay, more reusing), and keep it to top dress the plants in spring (if you go down that route just make sure your skins are really thoroughly dried out so they don't go moist and manky in storage), but I'm going to add what I've got now, and add more as I get more. I'm trying to get the bed filled with kitchen and garden scraps before winter sets in properly, so I can cover it and leave it to break down. I talk a bit more about ingredients for free compost in my October Garden Jobs post.

I didn't invent this free fertiliser out of banana peels hack, but I read about it such a long time ago that I can't remember where I heard about it. If anyone knows of the person who thought of it, let me know in the comments.