Growing Rosemary in Tana River

Soil suitability analysis based on Tana River's nutrient profile

Tana River County is a challenging environment for Rosemary (soil-match score 5/100) and will need significant amendment before planting. Local soils average pH 6.4 — slightly acidic to near-neutral and inside the 6–8 band Rosemary prefers, so no lime is usually required. The main gap is phosphorus and potassium — measured at N 1.04 g/kg, P 8.5 mg/kg, K 108 mg/kg against this crop's medium/medium/medium demand — so the fertilizer plan below prioritises closing those deficits. The county's predominantly sandy soils suit Rosemary, which favours sandy loam. At 200 m, the county sits below Rosemary's preferred altitude range (800–2400 m), which limits yield potential due to heat stress. Rosemary's full potential is about 2,500 kg/acre (~KES 375,000/acre at KES 150/kg), but at Tana River's 5/100 suitability a realistic target here is closer to 156 kg/acre (~KES 23,400/acre) unless the constraints above are addressed.