Growing Rosemary in Vihiga

Soil suitability analysis based on Vihiga's nutrient profile

Vihiga County is a challenging environment for Rosemary (soil-match score 35/100) and will need significant amendment before planting. At an average pH of 5.62 the soil is slightly acidic to near-neutral, below Rosemary's preferred 6–8 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. Nitrogen (1.02 g/kg), phosphorus (14.8 mg/kg) and potassium (164 mg/kg) all meet Rosemary's requirements, so a maintenance fertilizer programme is enough. Rosemary prefers sandy loam soils, while Vihiga is largely clay loam, 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 Vihiga's 35/100 suitability a realistic target here is closer to 1,094 kg/acre (~KES 164,100/acre) unless the constraints above are addressed.