Growing Rosemary in Kwale

Soil suitability analysis based on Kwale's nutrient profile

Quick answer

Generally not ideal — Kwale is poorly suited to Rosemary. Kwale's soil (pH 6.76, near-neutral) gives Rosemary a suitability score of 5/100. Match fertilizer to Kwale's nitrogen and phosphorus levels for the best result.

Kwale County is a challenging environment for Rosemary (soil-match score 5/100) and will need significant amendment before planting. Local soils average pH 6.76 — 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 0.93 g/kg, P 9.8 mg/kg, K 131 mg/kg against this crop's medium/medium/medium demand — so the fertilizer plan below prioritises closing those deficits. The county's predominantly sandy loam 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 #73 soil match of the 106 crops we assess for Kwale County. Rosemary's full potential is about 2,500 kg/acre (~KES 375,000/acre at KES 150/kg), but at Kwale'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 Kwale's soil: Dhania, Pigeon Peas, and Mango — each scores higher on the same soil.

5Suitability score

Soil & climate match

FactorKwale soilRosemary needsStatus
pH6.7668OK
Nitrogen0.93 g/kgmin 0.8 g/kgOK
Phosphorus9.8 mg/kgmin 12 mg/kgLow
Potassium131 mg/kgmin 150 mg/kgLow
Rainfall900 mm400–900 mmOK
Altitude200 m800–2,400 mLow

Planting calendar for Kwale

Long Rains· AprilJuneMain season here

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

Short Rains· NovemberJanuary

November
Cutting Establishment
December
Weeding
January
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 Kwale
0.250.2

Kwale's nitrogen (0.93 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 Kwale156 kg/acre
Estimated revenueKES 23,400/acre
Adjusted for Kwale'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