Growing Onions

Botanical Name:

Allium cepa (and others)

Description:

Onions are the bulbs of plants in the lily family known for their strong, distinctive taste and flavor. The bulbs generally have a papery outer skin surrounding a smooth, fleshy inner core.

Planting Time:

Plant onion sets and transplants outdoors when soil temperatures reach 35ºF. Seeds can be sown directly into the ground when soil temperatures reach 40ºF. In milder climates, plant green onions in the fall as late as 4 weeks prior to the first frost.

Exposure:

full sun

Soil:

well-drained, well-worked, nutrient-rich soil with a pH of 6.0.

Planting:

Seeds should be sown thinly at a depth of _ to _ inch and spaced 1 inch apart. Bulb onion sets should be planted 4 to 6 inches apart in rows 1 to 2 feet apart. Green onions can be planted closer together. When planting sets, keep the pointed ends up and covered with 1 inch of soil.

Watering:

Keep soil consistently moist to prevent bulbs from drying and splitting. Stop watering when tops turn yellow and onions are nearing harvest.

Maintenance:

Thin seedlings and transplants as necessary for development and mulch around plants to control weeds and conserve soil moisture. Take care when cultivating around plants to avoid disturbing the shallow roots. Remove onions that start to bolt (set seed).

Harvesting & Storage:

Harvest onions as your need them. When tops start to turn yellow and fall over, bulb onions can be lifted from soil and cured for storage. Store them in a warm place (out of direct sunlight) for 2 to 3 days. When dry, trim off tops and store bulbs in a mesh bag or leave tops on and braid them together to hang for storage. Refrigerate green onions for up to 1 week.

Diseases and Pests:

Watch for thrips or onion maggots. Keep plants free of weeds to eliminate hosts and discard infected plants.

Tips to Success:

Cure onions thoroughly at warm temperatures and store in a cool, well-ventilated place to reduce the chance of "neck rot" after harvesting.