Propagation and planting:

Onions are propagated sexually by use of seeds or asexually through sets. Where seeds are used, they may be established directly in the main field or started in a nursery and later transplanted when seedlings are pencil thick to the main field at a spacing of 30cmx10cm. Where established directly, thinning has to be done when the plant establishes. Transplanting eliminates the need for thinning but the method is very tedious.

Seed rate:

142g/acre. The use of sets allows for production of earlier green onion. Sets are planted at 2.5cm–5cm apart for green onions or 8-10cm apart for bulbs.


Around eight tonne/acre of well-decomposed organic matter before planting. 80kg/acre DSP at transplanting. This is very important because onions are very sensitive to phosphorus deficiency. 121kg/acre CAN when plants start growing after transplanting to encourage early vegetative growth, which may be applied in two splits.


Only done when the crop is grown under insufficient rainfall. If practised, irrigation should be stopped 2-3 weeks before harvesting to give the bulbs time to cure.


Should be done regularly to remove weeds within and between rows. As bulbs form, avoid earthing up otherwise moist conditions may encourage rotting of the bulbs or development of thick necks. Instead of earthing up, dearth to encourage expansion of bulbs.


Bulbs mature from 140 days depending on cultivar and weather conditions. Bend the necks as soon as tips of leaves begin to turn yellow or when around 10 per cent of crop is dry and leave the crop to dry for 14-21 days before harvesting (digging bulbs up). This treatment makes bulbs to have a smooth closure and minimises thick necks. After harvesting, bulbs should be cured before storage.


Involves removal of the tops and then covering the bulbs to protect them from excessive heat from the sun or any form of moisture. Tops are cut off by hand, shears or knife leaving 1-2.5cm of dried tops attached to the bulb, otherwise the bulb will decay. Very dry conditions during curing will dehydrate the bulbs while very humid environment encourages fungal growth. Cool slightly humid conditions are ideal for curing. While in this environment, roots should be cut to 1cm and the bulbs left in this environment for 2-3 weeks depending on the weather. The cool environment will encourage toughening of the scaly leaves to be able to protect the inner flesh. Field curing may also be done where after bending the tops, the bulbs are uprooted and spread on the ground so long as there is no excess sun. After curing, it is recommended to pack the bulbs in open ventilated boxes/nets and store them in a cool dry environment with good ventilation.

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ii. Where can I buy the seeds?

Seeds are available from firms like Kenya Seed Company, Amiran Kenya Ltd, Royal Seed, Simlaw Seeds and others that are certified.

iii. Can I be linked with potential market?

You cannot lack market for onions in groceries, hotels, and open air markets or when the onions are ready, you can advertise in the buyers and sellers column in Seeds of Gold.

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