Banana Circle

A banana circle is a pit with a ring of plants around it. The soil dug out is heaped into a low bank at the edge, bananas and other hungry plants go on that bank, and the pit is filled with coarse organic matter - prunings, leaves, spent stems, weeds. It rots where it lies and the plants on the rim feed on what it releases, so a heavy feeder sits beside its own supply of food and moisture.

Everything rests on whether the ground under the pit will take water. Bananas want soil that drains well and will not stand wet feet, which is why they go on the bank and never in the hole. Dug into ground that sheds water rather than absorbing it, the pit becomes an airless sump with dying plants around it, which is the usual way it fails. Spacing decides whether there is fruit at all: stems 2.4 to 3 m (8 to 10 ft) apart can fruit and the 0.6 to 0.9 m (2 to 3 ft) used for ornamental clumps cannot. Each clump is kept to five or six stems, and a stem that has fruited is cut at ground level and returned to the pit. Frost takes the leaves and a hard freeze kills a plant to the ground, which it regrows from only where the underground stem base stayed insulated. Wind on wet soil with a bunch of fruit overhead topples stems, so an open site needs shelter or ties.

Feeding the pit with household wash water is common and it forces a choice. Guidance on reusing that water rules it out on root crops and on any edible part it touches, and treats kitchen and dishwasher water as too dirty to use at all - yet root crops like taro are what a ring of this kind yields most reliably. The build is therefore either rain and compost with root crops on the rim, or bath and laundry water with only the fruit taken. That water also carries salt and boron, and since the pit has no outlet they build up around the roots with nothing to flush them, the slow failure this has no cure for. Water must not stand in the pit either, so what decides the size is how fast the soil takes water in rather than how big the hole is.