Profitable Onion Farming in Kenya: A 2026 Step-by-Step Guide to High Yields

Onion farming in kenya  (specifically Red Bulb Onions) is one of the most profitable ventures because onions are a staple in almost every household. With a maturity period of 3–4 months, you can achieve two harvests a year. Although this statement may sound cliché for most people who have tired it and failed. All the same with good timing and efficient resource utilization you truly can be a millionaire form one acre of onion farming.

Profitability Analysis and Finding the Right Market in Kenya

Before you dig, know your “when.”

• The Goal: Aim to harvest during the off-peak seasons (January–March or July–August) when supply from Tanzania is low and prices in markets like Wakulima,Marikiti or Gikomba skyrocket.
• The Variety: Go for high-yielding hybrids like Red Pinoy, Red Coach F1, or Russet F1. They have a long shelf life and the deep red colour Kenyans love.

Step-by-Step Farming Guide

Step 1: Ecological Requirements and Land Preparation for Bulb Onions

• Soil: Onions thrive in well-drained, sandy loam soil with a pH of 5.8 to 6.8.
• Location: Best regions include Kajiado, Narok, Kirinyaga (Mwea), and Nyeri.
• Tilling: Plough the land deeply to remove weeds. Break the soil into a fine tilth (smooth texture) to allow easy bulb expansion.

Step 2: Managing Your Onion Nursery and Transplanting for Success

Most farmers start in a nursery before transplanting.

1. Create raised beds (1 metre wide).
2. Sow seeds in rows 15cm apart and cover with a thin layer of soil/mulch.
3. Water regularly for 6 to 8 weeks until the seedlings are “pencil-thick.”

      Transplanting

1. Spacing: Space seedlings 10cm apart within the rows and 15cm between rows.
2. Depth: Do not plant them too deep; the base should just be covered by soil to allow the bulb to form on the surface.

Step 3:Essential Crop Care: Irrigation, Fertilization, and Pest Control

• Water: Onions need consistent moisture. Drip irrigation is highly recommended in Kenya to save water and prevent fungal diseases like Purple Blotch.
• Fertilizer: Use DAP during planting for root development. Top-dress with CAN 4 weeks after transplanting and NPK during the bulb formation stage.
• Pest control is quite critical for onions . Thrips is the most dominant pest you should tackle from the onset .
• Common onion diseases in Kenya include fungal infections like Purple Blotch (Alternaria porri), Downy Mildew (Peronospora destructor), Rust, White Rot, and Neck Rot, alongside bacterial diseases such as Bacterial Soft Rot. These diseases thrive in warm, humid conditions and are often managed through proper crop rotation, fungicide application (e.g., Ridomil), and avoiding over-irrigation.
  

  Key Onion Diseases in Kenya

  • Purple Blotch (Alternaria porri): The most common disease, characterized by small brown spots that develop into elliptical lesions with purple centers on leaves, causing premature leaf death.
  • Downy Mildew (Peronospora destructor): Appears as a white-grey fuzzy growth on leaves, turning them pale green then yellow.
  • Bacterial Soft Rot (Erwinia carotovora): Causes bulbs to become soft, mushy, and smelly, often starting at the neck.
  • Neck Rot (Botrytis spp.): A post-harvest disease causing softening and browning of the neck tissues, turning them into a grey mold.
  • Rust (Puccinia allii): Small, powdery white to orange, and eventually dark red spots on leaves.
  • White Rot (Sclerotium cepivorum): A soil-borne disease causing leaves to yellow and wilt, with white, fluffy fungal growth on the roots and base.
  • Damping Off: A nursery-stage disease causing seedlings to rot at the base.

  Management and Control

  • Chemical Control: Use fungicides like Ridomil Gold, Mancozeb, or Score for fungal issues.
  • Cultural Practices: Rotate crops to avoid soil-borne diseases, ensure proper spacing for air circulation to reduce humidity, and avoid excessive watering.
  • Storage: Proper curing of onions after harvest helps prevent neck rot.
  • Pest Management: Control onion thrips, as they spread viruses and damage leaves, making them prone to infections

   

Step 4: Harvesting and Curing Techniques to Maximize Shelf Life

1. The Sign: Harvest when 75% of the tops (leaves) have fallen over and turned yellow.
2. Curing: This is the most important step for shelf life. Leave the onions in the sun for 2–3 days, then move them to a shaded, well-ventilated area for 2 weeks until the “necks” are dry.

3. Costs & Returns (Estimated per Acre)

• Initial Investment: Approx. KSh 100,000 – KSh 150,000 (Seeds, fertilizer, labour, and chemicals).
• Yield: A well-managed acre can produce 10 to 15 tonnes.
• Profit: At a conservative price of KSh 60/kg, 10 tonnes earns you KSh 600,000. After expenses, your net profit can hit KSh 450,000.

FAQ

Q: Can I grow onions in a greenhouse?
A: It’s possible but not recommended. Onions need a lot of ventilation and space. Open-field farming with drip kits is more cost-effective.

Q: Where can I buy quality seeds?
A: Visit licensed agrovets or companies like Kenya Seed Company or Simlaw Seeds.

Q: How do I deal with Thrips?
A: Thrips are the “enemy number one” of onions. Use recommended pesticides like Occasion Star or Profile from your local agrovet as soon as you see silver streaks on the leaves.

Pro-Tips:
“Don’t sell your onions immediately after harvest if the price is low. Because if  they are cured, you can store them for up to 3 months and wait for the market price to double!”

Also before embarking on the venture learn pest control and proper feeding routine, this will guarantee you the astronomical tonnage per acre.