Growing Onions in Kenya: Tips for Soil Preparation, Seed Selection, Irrigation, and Harvesting

Onions are quite popular in Kenya. Onions are used to cook nearly all meals because they have many benefits to our health.

Onions grow well in fertile soils. You need to check if your soil is suitable to grow onions by having it tested in a professional laboratory like Crop Nuts. You can also reach out to me at 0793387901 to get guidance on this.

  • The soil test will enable you to figure out how fertile your soil is
  • The best type of fertilizer to use on your soil
  • Which type of crops you can grow on your farm

Onions dislike heavy soils such as clay and will perform poorly. Your soil needs to be well-drained and deep.

Onions grow well in soils with a pH between 6.0-6.8. Soils with lower pH values will affect the crops’ ability to take up nutrients.

Onions grow well in high-altitude regions that get a lot of rain from 500-70mm. The temperature required for good onion growth is between 15-30 degrees.

Land Preparation For Growing Onions in Kenya

Get a tractor and plow your land well. Make sure that all the soil lumps are broken down. It is recommended that you mix your soil with well-decomposed manure to add nutrient value.

Your soil test results will tell you which type of fertilizer to use on your farm. You are however required in most cases to use NPK fertilizer for growing onions.

NPK fertilizer contains; Nitrogen, Phosphorous, and Potassium, with small amounts of trace minerals.

How To Choose The Right Onion Seeds To Grow

It is always cheaper to buy seeds if you want to start onion farming. If you are in a bit of a hurry to grow and harvest your onions then you can buy from seedling companies.

Onions seed varieties available in Kenya include;

  • Red Creole
  • Bombay Red
  • REd Pinnoy
  • Texas Grano
  • Super Yali

There are other available varieties in the market that you can choose from.

The benefits of buying certified seeds are as follows;

  • You will get a germination rate between 95-100%. This means many seeds will grow and therefore you will use fewer seeds.
  • Hybrid-certified seeds are resistant to some diseases
  • Certified onion seeds have a longer shelf life

Transplanting Your Onions

It only takes 4 weeks for you to transplant onion seeds to the main farm. Check your onions and see if they have a waist as thick as a pencil.

Photo Credit: Dry Land Seeds

Irrigate your seedlings with water thoroughly during the transplanting day. This will help reduce transplant shock and increase your chances of success.

Onion Transplanting Process in Kenya

  • The onions in the nursery will need to be prepared before going to the main field. Gradually reduce the daily irrigation and remove the shade netting covering them.
  • Transplant your onions when the weather is cool. It’s usually best to do it early in the morning or in the evening.
  • Flood the transplant beds with water to prevent transplant shock. You should also remember to irrigate the nursery before transplanting to loosen the soil and provide relief to the plants.
  • Transplant the large, healthy seedlings first. Leave the small ones to continue growing as you will use them as replacements down the line.
  • Make a raised bed that is 1m wide and 30cm high. This is where you will transplant the onion seedlings.
  • Ensure you have already installed an irrigation system before you start the transplanting process.
  • Plant the seedlings 10 cm apart on the bed. Please confirm with the above image.
  • Insert the onion seedlings in holes 1.5 cm deep and then firm up the seedling base with the surrounding soil.
  • Top dress your seedlings with 2 bags of CAN per acre when your seedlings have started to grow well. This is after a month.

Onion Farming irrigation System

Onions require constant moisture to thrive. This means you will have to install a reliable irrigation system for your farm.

Go ahead and buy a drip irrigation system from Makimara. A drip irrigation system will help you grow your crops at ease, free from irrigation woes.

An onion drip irrigation system will give you the following benefits;

  • Water goes directly to the plant roots thus saving you water.
  • You will have fewer weeds on your farm because they will not be getting any water.
  • Less fungal diseases
  • It will be an automated system that requires less effort to operate

Pests And Diseases That Affect Onion Crops

Onions suffer from the following conditions that can be treated using approved chemicals found in the agro vet.

Purple Blotch – This is a fungal infection. Apply fungicides to treat.
Downy Mildew -This is a fungal disease. Apply fungicides found in agro vets.
Thrips – These are common pests that affect onions. They can be treated using chemicals that repel thrips.

Harvesting Onions in Kenya

  • Harvest your onions when the base of the plant is about to crack.
  • The leaves will start to bend and turn yellowish.
  • Start bending the top of the onions so that the harvesting process can commence. Bend and leave them. This must be done when the rains have stopped.
  • Pull all the onion bulbs from the soil and let them cure on the surface of the soil.
  • Leave the onion bulbs on the ground for 10 to 14 days. They should not go beyond 14 days for they might start to rot.
  • Cut the neck of the onions when they feel dry. This should be done 3.5cm from the neck. Clip off the roots in the process.
  • Grade and choose the best onions for different market segments.
  • Store your onions in net bags, not sacks. Onions can be stored for up to 6 months.
  • Start selling your produce.


  1. Don’t Lose Your Plot
  2. Dry Land Seed
  3. Shamba Shape Up
Joseph Boit
Show full profile Joseph Boit

Joseph is a social entrepreneur with a curious mind and a love for farming. Big dreamer and a technology enthusiast.

Show all Most Helpful Highest Rating Lowest Rating Add your review
  1. Please need More assistance in onion farming, I’m a new in onion farming in kenya

Leave a reply

Boit Academy
Register New Account
Welcome to Boit Academy
Shopping cart