Growing Pyrethrum in Tharaka Nithi
Soil suitability analysis based on Tharaka Nithi's nutrient profile
Generally not ideal — Tharaka Nithi is poorly suited to Pyrethrum. Tharaka Nithi's soil (pH 4.99, strongly acidic) gives Pyrethrum a suitability score of 31/100. Apply agricultural lime before planting to unlock phosphorus and lift the score.
Tharaka Nithi County is a challenging environment for Pyrethrum (soil-match score 31/100) and will need significant amendment before planting. At an average pH of 4.99 the soil is strongly acidic, below Pyrethrum's preferred 5–6.5 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. The main gap is phosphorus — measured at N 1.23 g/kg, P 19.6 mg/kg, K 211 mg/kg against this crop's medium/high/medium demand — so the fertilizer plan below prioritises closing that deficit. The county's predominantly sandy loam soils suit Pyrethrum, which favours loam. At 1100 m, the county sits below Pyrethrum's preferred altitude range (1800–3000 m), which limits yield potential due to heat stress. On ShambaIQ's soil-match model, Pyrethrum is the #96 soil match of the 106 crops we assess for Tharaka Nithi County. Pyrethrum's full potential is about 500 kg/acre (~KES 140,000/acre at KES 280/kg), but at Tharaka Nithi's 31/100 suitability a realistic target here is closer to 194 kg/acre (~KES 54,320/acre) unless the constraints above are addressed.
Better matched to Tharaka Nithi's soil: Avocado, Macadamia, and Cassava — each scores higher on the same soil.
Soil & climate match
| Factor | Tharaka Nithi soil | Pyrethrum needs | Status |
|---|---|---|---|
| pH | 4.99 | 5–6.5 | Adjust |
| Nitrogen | 1.23 g/kg | min 0.8 g/kg | OK |
| Phosphorus | 19.6 mg/kg | min 20 mg/kg | Low |
| Potassium | 211 mg/kg | min 150 mg/kg | OK |
| Rainfall | 900 mm | 900–1,500 mm | OK |
| Altitude | 1,100 m | 1,800–3,000 m | Low |
Top dressing guide
Tharaka Nithi's nitrogen (1.23 g/kg) already meets Pyrethrum's 0.8 g/kg requirement, so this is a maintenance rate.
Recommended seed varieties
No variety in our list is specifically rated for Tharaka Nithi's 1,100 m altitude and 900 mm rainfall, so all 2 are shown. Confirm with your agrovet before buying.
Economics
Fertilizer prices
Green = subsidized · (Commercial) per 50kg bag