Growing Rosemary in Tana River

Soil suitability analysis based on Tana River's nutrient profile

Quick answer

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.

5Suitability score

Soil & climate match

FactorTana River soilRosemary needsStatus
pH6.468OK
Nitrogen1.04 g/kgmin 0.8 g/kgOK
Phosphorus8.5 mg/kgmin 12 mg/kgLow
Potassium108 mg/kgmin 150 mg/kgLow
Rainfall400 mm400–900 mmOK
Altitude200 m800–2,400 mLow

Planting calendar for Tana River

Long Rains· MarchMay

March
Cutting Establishment
April
Weeding & Light Feeding
May
Harvest & Pruning

Short Rains· OctoberDecemberMain season here

October
Cutting Establishment
November
Weeding
December
Harvest & Pruning

Top dressing guide

Product
CAN
Timing
Twice per season
Instruction
Light feeder — over-feeding reduces oil content and hardiness.
Bags per acre in Tana River
0.250.2

Tana River's nitrogen (1.04 g/kg) already meets Rosemary's 0.8 g/kg requirement, so this is a maintenance rate.

Economics

Market priceKES 150/kg
Expected yield in Tana River156 kg/acre
Estimated revenueKES 23,400/acre
Adjusted for Tana River's 5/100 suitability. Under ideal conditions Rosemary can reach 2,500 kg/acre (~KES 375,000/acre) — attainable here only after the climate and soil constraints below are addressed.

Preferred textureSandy Loam

Fertilizer prices

DAP
KES 3,500(6,500)
CAN
KES 2,875(5,700)
NPK 17:17:17
KES 3,275(5,600)
Urea
KES 3,500(5,500)
Lime
KES 1,500(1,800)

Green = subsidized · (Commercial) per 50kg bag