Growing Rosemary in Kirinyaga

Soil suitability analysis based on Kirinyaga's nutrient profile

Rosemary can be grown in Kirinyaga County, but the soil scores 50/100 and needs targeted management to reach full potential. At an average pH of 5.31 the soil is moderately acidic, below Rosemary's preferred 6–8 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. Nitrogen (1.36 g/kg), phosphorus (12.5 mg/kg) and potassium (177 mg/kg) all meet Rosemary's requirements, so a maintenance fertilizer programme is enough. Rosemary prefers sandy loam soils, while Kirinyaga is largely clay, so drainage and organic-matter management matter more here. Rosemary's full potential is about 2,500 kg/acre (~KES 375,000/acre at KES 150/kg), but at Kirinyaga's 50/100 suitability a realistic target here is closer to 1,563 kg/acre (~KES 234,450/acre) unless the constraints above are addressed.