Jennie sent us some great information about African “keyhole”gardening and bag gardening. Whenever I learn how people in other cultures garden in ways that conserve and sustain scarce resources, I’m always impressed (and sometimes a little guilty feeling for our society’s inefficient use of precious resources). Jennie writes:
What’s a Keyhole garden?
My brother recently sent me links to YouTube videos of sack and keyhole gardens promoted in Africa as alternative raised beds for a household’s vegetable growing. I was very interested and am thinking how and whether to adapt the ideas to try here.
Keyhole gardens are a different type of raised bed intended to be more or less permanent and sustainable through an ongoing composting in a central “basket”. In fact, the kitchen wastes added to the center may provide all the fertilizer and irrigation necessary for successful vegetables in the bed, which is a convenient height about 2 feet above ground level. There are many variations, but in general stone or bricks are recommended for the outer wall, mortared or not, while strong wire mesh or woven saplings and branches make the inner basket tube. Between these walls, the 2-3 ft wide planting area is filled at first with a good deal of fibrous material such as corn husks, coir, straw, and cardboard along with soil and/or compost, manure, potting media, mixed up or possibly layered as in a lasagna garden, finishing with several inches of good growing medium on the top layer. Kitchen scraps are to be dumped upon additional fibrous material in the central basket.
In dry climates or seasons, the water used to wash vegetables and dishes, etc., will be dumped into the center along with scraps and peelings. Since kitchen scraps are around 90% water, which is released during decay, this may provide sufficient moisture for the whole garden. Crops should grow as vigorously as on a typical compost heap, and the very active soil ecosystem may limit disease-causing fungi, as will the lack of surface or overhead irrigation. Crop rotation may still be needed to optimize nutrient use and plant health.
Such a bed can certainly be an attractive landscape feature like a large wishing well, but in the poverty of Africa where this instructional video was made, the efficiency of recycling water and organic material to raise high-quality food in a small space is certainly the primary advantage.
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Likewise, their take on sack gardening is different from ours in using tall sacks that would hold a person or two, and constructing a central column of rocks to allow water penetration into the whole container. Then they insert plants into the sides of the sack, gaining greater growing surface area than most containers while limiting water evaporation. Clearly less permanent and less attractive, these provide another low cost method of using compost and raised beds to maximize production and minimize losses to weeds and soil compaction. Such “kitchen gardens” do not replace agriculture but supplement a single household food supply with high quality ingredients that are consumed fresh, at their nutritional peak, with very little loss in harvest, storage or shipping.
Before writing these ideas off as suitable for hot dry places, do a search and see how many keyhole gardens are in the UK and in our northwest!
Monroe County Master Gardener Association 