Early in the spring, a reader introduced me to a gardening concept I’d not heard of: “keyhole gardening.” She was trying to decide whether to arrange her vegetable garden in boxed raised beds or to experiment with a “keyhole” arrangement.
We’re all familiar with the raised beds that so many gardeners feel they must use for growing vegetables. They’re usually built with enclosures constructed with wood.
The keyhole garden concept originated in Africa as humanitarian agencies concerned with food insecurity sought to design a garden type that would be cost-free and could be tended by people weakened by illness or malnutrition — and by children.
Keyhole gardens were constructed in schools to provide vegetables for school lunches; the children who helped to build and tend the gardens brought their knowledge home to educate their parents.
A keyhole garden is a circle with a diameter of two metres, raised above the ground and bordered by walls made of “found” or recycled materials such as stones, bricks, blocks, sand bags or old boards dug into the ground.
The usual height is one metre, though this can vary according to the needs of the gardener(s).
The “keyhole” is a wedge cut out of the circle to easily access the centre, where a circle of chicken wire with about a 45-cm diameter is set up to receive compostable materials and water.
Anything that will allow water to pass through can be used to form the “compost basket” circle, which is secured in place with stakes or rebar. The design allows every bit of the garden to be within easy reach.
The bed is filled, “lasagna” style, with a base of cardboard or paper, followed by layers of manure, leaves, chopped straw, or/and old potting mix, topped with good compost or soil and allowed to settle, with watering, before planting. The soil surface is made to slope downward to the outer border wall. This helps to direct moisture and leached nutrients from the compost basket out into the bed.
The enclosure holding composting matter needs to extend above the soil level at the centre of the bed. A cover over it helps to conserve moisture and also to deflect excessive water during heavy rains.
In Africa, keyhole gardens are commonly located close to the kitchen and used to raise leafy greens, herbs and root crops.
These gardens are ideal for intensive plantings. They take little space and are water-thrifty and self-sustaining. And they can be built at little or no cost.
Keyhole or box? Making a choice between a keyhole design, a rectangular box, or no enclosure at all for planting is purely a matter of personal preference. I’ve never been drawn to a “boxed-in” style of gardening, and prefer not to use enclosed beds. I see raised-box plots as limiting, and unnecessary.
Most of my vegetable plots are raised slightly (using only a rake), with a rakes-width pathway between them, but without any enclosures made with store-bought materials. Being able to easily reconfigure the plots from year to year, incorporating previous pathways into beds for planting, helps to maintain soil fertility.
Still, the keyhole concept attracts me for its self-sustaining design. A keyhole garden would be ideal as a kitchen salad and/or herb garden in a small space close to a dwelling.
Notes from the garden. I’m fond of edibles that are beautiful as well as tasty. I love the look of a large artichoke plant loaded with big buds, ready for removal and feasting on.
Some lettuces are gorgeous. My prettiest planting of early summer lettuce is, as usual, the Johnny’s Selected Seeds Salanova Home Garden Mix, a bend of green and red butterhead and oakleaf lettuces. They are growing in the afternoon shade of staked tomato plants trained against wire fencing, where they take almost no space and bring elegant notes to a vegetable plot.
Garden mirth. Seen in the latest email bulletin from Dig This (local stores with gifts and gear for gardeners): A gardening apron with the bib bearing a message in brightly coloured letters that say: “Sometimes I Wet my Plants.”
Garden event
Garden picnic. The Horticulture Centre of the Pacific, 505 Quayle Rd. in Saanich, is hosting a Picnic in the Gardens event on Wednesday, July 25, from 5 to 8 p.m. Bring along a picnic and enjoy your meal in a beautiful setting while listening to live local music. Admission is by donation. Details at hcp.ca.
