A banana circle is a great way to grow bananas, or any other tree/herb (bananas are actually a herb) that require a lot of water. So if you don’t like bananas, you could plant papaya or willow (which is great for mulch). At the PDC we learnt how to make one and while working at a farm here on Penang, another one was being constructed, so I took some pictures.
First of all, why would someone want a banana circle? There are many benefits, this is a great way to get rid of kitchen scraps or other organic wastes. In the tropics, it is amazing how fast organic material can break down here. That organic matter will be then utilized by the bananas. Typically there are banana clumps of three or four. In banana clumps, you have to mulch each clump, but with a banana circle you can essentially cut you mulching work in half (a banana circle will have 7 or 8 bananas).
The way the banana circle is designed will cause the organic matter to be leached into the soil and not across the soil (as with clumps). In clumps you may have too many banana plants and as a result your bananas will be small and spread across to many banana plants, thereby creating more work for you.
A banana circle creates edge, edge is important, ask a forester where the greatest amount of diversity of plants are in a forest, and they will tell you it is on the side of the road right of way, near a stream bank or near the shore of a lake. All of these places have edge and edge create a more diverse site which can support a greater amount of diversity. The same is with a banana circle, and as such, you can grow more then just bananas.
The first step is to dig a hole (~2m in diameter and ~1m deep). In the end the hole should look like a mini crater, the hole should be fairly concave and the sides shouldn’t be too steep.
The next step is to pull the dirt around the edge of the hole and make a brim or a mound around the hole.
Now it is time to plant. Plant what you want to grow there, whether it is a banana, papaya, willow or something else.
This is where permaculture really shines. Now plant some other species, and really you can plant anything you can think of. Near the inside of the hole it will be wetter, this is where you plant something that likes the water, like taro, yam, or ginger. On the crest (where you planted the banana), plant some sweet potato and some lemon grass. Near the bottom of the slope plant some beans (which will climb up the banana trees). To add an extra benefit, place a grate in the middle of the circle and have a shower in the middle of the banana circle and all grey water from the shower will be captured and used for banana growth.
With the use of a banana circle, there is no need to make compost (which is a lot of work), and there is no need to burn any organic matter. It is unfortunate here, so many people will rake up leaves, twigs, kitchen waste and coconut husks into a pile an burn it. Why would someone do this when they can use this great organic matter to make food? There just isn’t any reason why someone should burn waste in the tropics (or temperate regions for that matter).