Onion (Red) 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 Full sun. Frost tolerant Yes. Feeding Mix a balanced organic fertilizer into the bed or row before planting your onions, taking care to get it into the soil below the plants. Do not feed plants that are nearing maturity if you want very sweet onions. Spacing Single Plants: 5" (15cm) each way (minimum) Rows: 3" (10cm) with 7" (20cm) row gap (minimum) Sow and Plant If you don't start your own seeds, set out sets (small dormant bulbs) or pencil-size seedlings in spring, while the soil is still cool. Our Garden Planner can produce a personalized calendar of when to sow, plant and harvest for your area. Notes Onions respond to changing day length. Grow short-day varieties in southern latitudes. Long-day varieties work best in northern areas. Try growing different varieties from seed to explore differences in bulb color, size and shape. Harvesting Harvest young onions as scallions. When bulbs form and the tops of the plants fall over, pull them and cure in a warm place for about 10 days before storing. 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 (Red) Aphids (General) Onion Root Maggot Slug Snail Thrips Plant Diseases which Affect Onion (Red) Allium White Rot Onion Downy Mildew Onion Fusarium Basal Rot Onion Pink Root
