Banana trees like;
– Sun (for growth and light shade for fructification)
– Organic matter
– Light soil with good drainage
Banana trees dislike;
– Wind and associated drought
– Compact and heavy soil
The Banana circle, which is a round cluster of Banana trees is the best answer to these requirements;
– The center of the circle collect and mechanically store organic matter and humidity. The roots of the banana trees will develop mainly there to catch humidity and organic nutrients
– The cluster of trees act as a mutual wind protection
– The mount of the volcano border where are planted the banana trees is made of soft soil facilitating root development.
Banana will not grow on a soil compacted with clay. Roots will have problems to develop and water logging will provoke the stem to rot. In this type of situation a large hole is made to remove the clay and amend it with silt or sand as shown in the picture.
A rule; there is never enough mulch to feed a banana tree unless you use the banana tree to recycle used water. Even in the latter case the banana tree will prefer brown water recycling (rich in fibers) than for example sink water recycling. So; be generous with organic material and always keep the banana stems you cut (when collecting the bananas) back into the center of the circle.
Banana circles love waste water from human. It is a reason why Banana is a plant of choice in tropical Permaculture. For every spot where human use water (shower, sink, bio-digestor populated by water closets, urine disposal from dry toilets …) a Banana Circle can be setup to capture and reuse the polluted water. It is even advised not to gather all polluted water in one central place but spread the water usage recycling to various banana circles so to multiply this resource usage and make sure you capture all nutrients you can from human wastes.
Various strategy can be setup in case of recycling…
Corridor and vegetation stretching using Banana Circles
A corridor of vegetation between 2 banana circles can be created to speed up the vegetation (when in a rehabilitation focus) stretching process. In this case the terrain and the sectors analysis and existing vegetation situation may help to define the most protected and humid direction (wind, sun, rain) to ease the propagation and to localize the banana circles.
Waste water volume recycling
The tubulation populating a Banana Circle can be diverted or multiplied over time depending on the quantity of nutrients contained in the waste water, to create for example a second banana circle more down the hill and split the flow in two.
Spreading of recycled chemical elements
Exchanging the cut stem from one banana circle to another can be done depending on the type of human waste. For example if a banana circle receives water from a spot dedicated to washing clothes (washing machine or sink) you may expect a high level of phosphorus (sodium triphosphate compound) and other additives that, if considered as a pollution when in excess may become a resource if degraded and recycled in your garden.
Most of detergents have for example a pH>9.5 which can be useful if your land is very acidic. In this case you may add a certain quantity of sand and spongy mulch inside the banana circle hole and transfer it somewhere else after a while. The design of the banana circle should be adapted to this regular transfer and some soil analysis made time to time to analyze the speed of acidity change.
If you made a biodigestor by evapo-transpiration using building remains (cement blocks, concrete powder, …) you may expect your banana stems to have a high concentration of calcium and silica, etc…
Permaculture not only allow to get rid of pollution but help here to transform the waste in many useful resources; minerals and water.
Banana Circle and Swale for water run-off recycling
Since banana circle love water a good location is to position one down the hill of a swale on the top of the water lens. This strategy implies a two steps method; first build the swale then after a while use the sediments and sand accumulated in the swale by erosion from water run-off to create the soft ground for banana circle construction. If you use directly the soil down the hill you may assume that erosion has kept only hard soil not suitable for banana roots.
Banana Circle Shower
Organic degradation is quicker with the presence of a shower and requires regular addition. The good news is that the degradation will benefit the banana trees intensively.
The picture below shows the evolution of a banana circle shower before (just after having planted the banana trees) and after (after few months). The design has now evolved with a dome in the center.
Each stem will give a cluster of bananas. Picking up banana one by one as they get ripe allow to avoid the full cluster to ripe at the same type. This happens when removing the cluster of banana at once. However letting the banana ripe on the tree will mean birds taking their share. Once removed all bananas the stem is cut in pieces (e.g. 50 cm long) and put back into the center of the banana circle as organic matter. You may as well remove the wilted leaves regularly if you have time and not too many of banana trees and dispose them in the center of the circle as well.
Some photos of Banana Circle showing the evolution of the plants;
Banana Circle – Before, on a future outdoor shower
Banana Circle – After, on the outdoor shower
Before, getting the gray water from a sink
After, getting the gray water from the sink. The banana circle provides, once adult, shade when cleaning the dishes.
Before. it will get the urine diverted from the dry toilets
After few months, photo taken from the cabin of the dry toilets. Urine contain a lot of nitrogen. In this case it will be important to return the trunks and leaves (after banana harvesting) to the center of the banana cluster since banana trees may have a lack of carbohydrates compared to nitrogen and water.