How to Grow Onions: A Comprehensive Guide for Beginners
Introduction
Onions are a versatile vegetable that can be used in a wide variety of dishes. They’re easy to grow, even for beginners, and they can be planted in both the spring and autumn.
Choosing Onion Seeds or Sets
You can grow onions from seed or from sets (small onions). Sets are easier to grow, but they’re more expensive to buy. If you’re buying sets, make sure you buy autumn- or spring-planting sets for planting at the right time.
Planting Onion Sets
Plant onion sets 10-15cm apart, allowing 30cm between rows. Plant them just below the soil surface, with just the tips showing. Water well after planting.
Planting Onion Seeds
Sow onion seeds indoors as early as January. Sow seed in a pot or tray of moist seed compost, about 1cm apart. When the seedlings are a few inches tall, prick them out and transplant into fresh compost. Once established, transplant seedlings into the garden, 10-15cm apart.
Caring for Onion Crops
Onions need well-drained soil, full sun, and regular watering. Fertilize onion crops with a nitrogen-rich fertilizer in the spring. Remove any flower heads that appear, as these divert the plant’s energy from bulb development to seed production.
Harvesting Onions
Onions are ready to harvest when the leaves droop over and turn brown. Gently loosen the soil with a fork and lift the onions out of the soil. Leave them to dry on a drying rack or similar before storing.
Storing Onions
Spread onions and shallots out on newspaper or racks to dry. They’re ready when their outer skins rustle when you touch them. Hang or string them in nets in a cool, dark, dry place. They should last for months.
Troubleshooting Common Onion Problems
- Onion fly larvae: Cover the sets with horticultural fleece to stop birds from pulling them up.
- Onion-neck rot: Don’t overcrowd when planting, and dry bulbs thoroughly before storing.
