At the entrance of the farm is a cowshed that houses 20 dairy cows that produce at least 500 litres of milk daily, according to Ms Karanja. At Sh50 a litre, she makes Sh25,000 daily from the animals.
Next to the cowshed is a pen that holds several healthy calves. Close by is a newly-constructed biogas unit that is being harnessed to obtain free power supply.
Three greenhouses, each measuring 50 x 100 feet, occupy a quarter of the farm. Here, Ms Karanja has planted green pepper, cabbages, carrots, onions, sukuma wiki and tomatoes.
“I used to sell 10 crates of tomatoes per week at Sh800 each. Now I sell different varieties of vegetables including tomatoes, onions, carrots, cauliflower and green beans,” she says adding that she earns about Sh50,000 a month from vegetables.
In one corner near the farm’s borehole is a 5m x 6m fish pond that holds at least 300 tilapia. Ms Karanja says the demand for fish has become increasingly high in Nairobi and she therefore plans to double the number by next year.
The story of the magic Sanla Farm, which rakes in close to Sh1 million per month, dates back 2008 when David Karanja (the husband) bought a half-acre plot in Ruai to build a home for his family.
“I said to myself that this land would not be just a homestead as he had intended, but also a source of living,” Ms Karanja says.
The mother of three started off with one Freshian cow that used to produce about 10 litres of milk daily.
“I felt an irresistible urge to buy more cows. Today I have 20 Freshian cows that produce about 500 litres of milk every day,” she said.
Thanks to her diligence, Ms Karanja has within five years earned millions of shillings and fame. In 2011, Sanla Farm was recognised by the Food and Agricultural Organisation (FAO) with an award as the Best Farm among small-scale farms in Nairobi.