Permaculture Project: Planted Compost Circle

The "Banana Circle" is a classic, but tropical, design.

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The Banana Circle is a classic Permaculture design. A circular pit is dug. The soil from the pit is used to build up walls around the pit. Bananas are planted in the wall. Any and all organic matter that would be added to a compost bin is added to the center of the pit. Over time the organic matter breaks down and provides a fantastic nutrient supply to the growing (and nutrient hungry) banana plants. This design illustrates Permaculture Principle Eight: Integrate Rather Than Segregate. This design integrates a compost pile and a food producing crop planting into one structure. This design automatically fertilizes itself as the organic matter breaks down into compost. This design protects from drought by having a huge pile of organic matter (which absorbs and stores large amounts of water) right next to the banana's roots. This design is brilliant!

But it is tropical.

Yes, I have a few banana tress in my backyard right now, but I'm moving in a few months, and I don't suspect I'll ever live in the tropics or sub-tropics again. 

One similar method that is being used with annual vegetable gardening is the Tomato Circle. The same basic premise is followed as the Banana Circle... a central compost pit with tomatoes growing all around. I particularly like the one design shown below. Note the "pit" is really more of a circular trench with a drain. This allows more focused water collection closer to the plants, but still allows an escape if too much water collects.

But this is for annuals.

A "Tomato Circle" is a growing trend.

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So how can I incorporate the concept of a Banana Circle in more temperate climates using perennial plants? I have yet to find anyone designing Planted Compost Circles (I don't know if there is an official name for these designs, so this is what I call them). I wanted to get a few of my ideas out there, and maybe spark better ideas from others. Here is what I have so far:

• Mixed Berry Circle - a few each of Goji, Goumi, and Nanking Cherry.
• Bramble Circle - a mixed variety of blackberries and raspberries.
• Gooseberry Circle - a mixed variety of Gooseberries. 
• Blueberry Circle - compost can be heavy on the "acid" content (i.e. pine needles).

As I come across more, or better, ideas, I'll post them here.