Spring onions also called scallions or green and bunching onions are basically young onions, harvested before the bulb has had a chance to swell. They are easy to grow and maintain. Consumers like them because they can be used in variety of recipes as seasoning in soups and salads.
George Muchiri from Nakuru County says as a farmer, planting spring onions can be a good addition since they mature fast and can be intercropped with slow-growing vegetables. Muchiri grows and sells the spring onions as supplementary business. He also farms potatoes and vegetables.
"Some varieties mature as early as eight weeks after sowing, while others go up to 16 weeks," says Muchiri.
White Lisbon scallion is a popular green onion seed that is sold in Kenya by Kenya Seed. It adapts well in growing in a wide range of ecological zones. It can be sowed directly onto the field or started in a nursery.
Spring onions can grow in a wide variety of areas, with any climate, since they can tolerate heat and cold. Spring onions do well in draining loose soils with a pH of 6.3 to 6.8. They do well in full sun but can tolerate partial shade.
Land and nursery preparation
When planting directly, make rows 30 centimetres apart.
Prepare a raised nursery at one metre wide and any length. You can apply phosphate fertiliser at the rate of 20 grams per square metre of nursery and make sure you mix the manure, fertiliser and soil thoroughly.
Prepare furrows that are two centimetres deep and five centimetres apart on the nursery bed. Sow the seeds onto the furrows and loosely cover with soil. You can apply a thin layer of mulch over the nursery to prevent the seed from being washed out of the bed during irrigation.
"After 10 days, your spring onion seeds will germinate. Remove the mulch and build a shade for young seedlings," says Muchiri.
Your spring onions will be ready for transplanting after six weeks. They should have a pencil-thick stem at the base and be 15 centimetres tall.
Transplant spring onion seedlings in the morning or evening, this protects the tender seedlings from being scorched. The spacing for spring onions should be eight centimetress. Water the field before and after transplanting.
Spring onions should be top-dressed four weeks after transplanting. CAN fertiliser should be applied as advised.
Pests and diseases
Diseases include black mould, botrytis leaf blight, downy mildew, fusarium basal plate rot, fusarium damping - off, pink root, rust, smut, white rot.
To control, treat seeds with fungicides, ensure the soil is not too wet or too dry and practice crop rotation. Pests include bulb mites, leafminers, onion maggots and thrips. Practice good sanitation and remove the affected onions from the farm.
Spring onions are harvested when the leaves are succulent and stems reach a diameter of 0.25 to 0.5 inches. Harvesting is done by uprooting the plant, cleaning, and tying them in bunches, ready to go to the market.
Market for spring onions is available. Muchiri sells his produce at Sh20 per kilogram and can make up to Sh80,000 from his farm in a good season. His farm can produce up to four tonnes of spring onions.