Growing Rosemary in Tana River
Soil suitability analysis based on Tana River's nutrient profile
Generally not ideal — Tana River is poorly suited to Rosemary. Tana River's soil (pH 6.4, slightly acidic) gives Rosemary a suitability score of 5/100. Match fertilizer to Tana River's nitrogen and phosphorus levels for the best result.
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. On ShambaIQ's soil-match model, Rosemary is the #66 soil match of the 106 crops we assess for Tana River County. 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.
Better matched to Tana River's soil: Sorghum, Cowpeas, and Pigeon Peas — each scores higher on the same soil.
Soil & climate match
| Factor | Tana River soil | Rosemary needs | Status |
|---|---|---|---|
| pH | 6.4 | 6–8 | OK |
| Nitrogen | 1.04 g/kg | min 0.8 g/kg | OK |
| Phosphorus | 8.5 mg/kg | min 12 mg/kg | Low |
| Potassium | 108 mg/kg | min 150 mg/kg | Low |
| Rainfall | 400 mm | 400–900 mm | OK |
| Altitude | 200 m | 800–2,400 m | Low |
Planting calendar for Tana River
Long Rains· March–May
Short Rains· October–DecemberMain season here
Top dressing guide
Tana River's nitrogen (1.04 g/kg) already meets Rosemary's 0.8 g/kg requirement, so this is a maintenance rate.
Economics
Fertilizer prices
Green = subsidized · (Commercial) per 50kg bag