Onion (Autumn planted) Growing Guide Allium cepa Crop Rotation Group Allium (Onion family) ● Soil Fertile, well drained soil with compost dug in. In clay soil, grow in raised beds or rows. Position Sun or partial shade. Frost tolerant Yes. Feeding Not normally required, though overwintered sets can be given a liquid feed in spring. Spacing Single Plants: 15cm (5") each way (minimum) Rows: 15cm (5") with 25cm (9") row gap (minimum) Sow and Plant Easiest to sow onion sets (tiny bulbs) which are planted direct into the soil from autumn onwards. Can also be grown from seed in which case start in pots under cover in late winter before planting out mid-late spring. Our Garden Planner can produce a personalised calendar of when to sow, plant and harvest for your area. Notes Japanese variety onion sets can be used to give an early harvest. Onion sets are also the better choice for heavier or wetter soils. Harvesting Harvest as soon as they reach a reasonable size. If storing them, wait until the tops start to die down and dry for about 10 days. Troubleshooting Weed early and often to keep onions growing strong. Seedlings are less likely to bolt (produce flowers) compared to bulb onions grown from sets. Planting and Harvesting Calendar < Back to All Plants Pests which Affect Onion (Autumn planted) Allium Leaf Miner Aphids (General) Millipede Onion Root Fly Slug Snail Plant Diseases which Affect Onion (Autumn planted) Allium White Rot Onion Downy Mildew Onion Fusarium Basal Rot
