To plant onions successfully, follow these key steps:
Preparing the Soil
- Choose a sunny spot with well-drained, fertile soil. Onions prefer soil with a pH between 6.0 and 7.5, ideally neutral to mildly alkaline
- Improve soil by mixing in aged compost or organic matter to enhance fertility and drainage
- Break up and level the soil, removing weeds. Lightly compact and rake to a crumbly texture
Planting Onion Sets (the easiest method)
- Plant onion sets when soil temperature reaches about 45-50°F (7-10°C), typically early to mid-spring after the last frost
- Make a shallow furrow or drill in the soil.
- Plant sets 2 cm (¾ inch) deep, just deep enough so the pointed tip is barely showing above the soil surface
- Space sets 5-10 cm (2-4 inches) apart within rows, and rows 25-30 cm (10-12 inches) apart
- Firm the soil gently around the sets and water well to settle them in
- Protect newly planted sets from birds by covering with fleece or netting until established
Additional Tips
- If soil is cold or wet, start sets indoors in trays and transplant later
- Onions can also be grown in large containers with peat-free compost, placed in a warm, sunny spot
- Keep soil moist but not waterlogged; onions have shallow roots and need regular watering when the top inch of soil dries out
- Mulch lightly with weed-free material but avoid keeping bulbs too moist
Summary of Spacing and Depth
Step| Depth| Spacing Between Plants| Spacing Between Rows
---|---|---|---
Planting Sets| 2 cm (¾ inch)| 5-10 cm (2-4 inches)| 25-30 cm (10-12 inches)
Onions planted this way will mature in about 80 days from sets, ready to harvest when bulbs are large or tops begin to wither
. This method ensures healthy growth and good bulb development for your onion crop