In capitalism one eats food they pay for. You pay for the food from your pocket or by farming it yourself.
Evidence shows most vegetables consumed by households in Nairobi are grown along polluted rivers and streams using wastewater - which contains heavy metals and other toxic chemicals.
The Nairobi County Assembly adopted the Water and Sanitation Services Policy last year which outlaws the use of sewage water and wastewater to irrigate crops.
For those interested in setting up a kitchen garden, here are some of the easy-to-implement technologies one could use to develop the system.
The wick irrigation gardenThis is a simple garden that employs use of jerry cans and a wick measuring 30cm long and 2cm in width. The wick - much like with a kerosene lamp - draws water up to the soil where the crop is growing. The can is sliced in such a way the lower half holds water in which the wick is dipped and the upper half holds the soil, the plant and the wick. Most medium-sized vegetables like spinach and cabbages would do well in a wick garden. Mounted on a wooden frame, the wick garden would easily fit in any amount of space.
tyre gardenDo you have used car tyres of any size? If you do, do not worry how to dispose of them. Cut the tyre to remove the inner rims on both sides. Place it on the ground to form a circle and fill it with soil and manure. The tyre garden can be used to grow herbs like rosemary, fruits like strawberry and vegetables like kales.
Simple drip irrigation gardenWith used plastic containers and a wall (or a pole) one can establish a simple drip irrigation garden. The best containers would be 5-litre jerry cans. The cans are cut in such a way they would be easy to fix on the wall or a pole and placed vertically one above another. At the top of the cans, a water-holding container with a hole at the bottom - from which water would drip when the cover is open - is erected and operated.
Micro gardenThe micro garden is simple to develop and best suited for city dwellers with nothing much than a balcony to grow food. It involves use of plastic containers like buckets to carry soil and manure. One can hang the buckets from the balcony ceiling or just arrange the buckets on the floor. The micro garden is watered regularly based on the crop's water needs.
The multi-storey gardenThis garden uses sacks and nets. One can also improvise with linen shaped like sacks. Holes with diameters measuring about 3cm are cut out and properly spaced on the sack. Soil mixed with manure is then placed in. Ballast (or medium sized stones) are stacked at the centre of the sack to form a midrib through which watering will be done. The sack is pulled up until it is full and upright. Vegetables - especially spinach and green collard (sukuma wiki) - are transplanted from a nursery into the holes on the wall of the sack and a few at the top.
Food robe gardenThe food robe garden is a vertical farm that combines micro-gardens and a vertical wooden structure designed to mimic shelves. The food robe structure needs to be erected by a professional who would ensure it is strong enough to carry the weight of several micro gardens. The height inside the shelves is determined by the natural height of the species grown.
Cone gardenThe shape of the garden gives it its name. The garden has rings of soil compacted together and held into place by a thick and strong plastic sheet. Each ring is smaller in diameter than the ring below it. The cone garden is ideal for a backyard kitchen garden as it would need slightly larger space to set up. Also, because it is bulky, the cone garden is erected directly on the soil surface. It looks like a steep hill with circular terraces. On each terrace, one can choose to plant a different species creating a collage that would both be a food source and aesthetically pleasing.
Moist bed gardenSome plants grow best in moist soils. For example, arrow roots (nduma) and sweet potatoes. Some species of collard greens and cabbages will also do well in a moist bed garden. The bed is constructed with impermeable plastic bags - preferably dam liners - that hold in the moisture; allowing the plants to take up most of it. A moist bed garden is watered regularly to make sure that the soil is always wet. There are two types of moist bed gardens: raised and sunken (sunk into the earth) moist bed gardens.
Staircase gardenThis is yet another variant of a vertical kitchen garden. A staircase garden is constructed using wood to create 'staircases' on which pails, wooden boxes, basins and similar micro gardens can be placed and arranged neatly. Like all vertical farms, the staircase garden allows one to use little space for more food production.
AquaponicsAquaponics would be the ultimate kitchen garden for a family that values animal proteins as well. Aquaponics mimic the natural ecosystem in which aquatic life lives symbiotically with terrestrial crops. Fish eat their food and release waste into the water. The waste is then metabolised by bacteria to form fertiliser for plants to use. The water - the plants having used up the nutrients - is clean enough to divert it back to the fish.
Hanging gardensHanging gardens can be set up using nearly any type of container. Are one-litre juice bottles all you have? You can definitely set up a hanging garden. The container is cut lengthwise to expose a larger surface area where soil mixed with manure can be placed. The crop is then planted. Watering is done twice per week. You however have to take care that you do not overcrowd a container, as this would stunt the crop due to competition for nutrients.