How to Grow Candy Onion
Allium cepa
Candy Onion is a flavorful allium prized for its sweet taste and reliable yield. Gardeners grow this easy-to-moderate variety to enjoy fresh bulbs in salads or cooked dishes while benefiting from good resistance against common root rot issues.
📷 Wikipedia: OnionStarting Candy Onion: indoors or direct sow?
🌾 Sow directly in the garden — Candy Onion is not usually started indoors.
Direct sow seeds outdoors rather than starting indoors, planting them 4 to 6 weeks before your local last frost date.
Soil, care & harvest
Prepare loose, fertile soil with a pH between 6.2 and 6.8 for best results. As a cool-season crop, sow seeds directly outdoors 4 to 6 weeks before the last spring frost date. Press seeds gently into the soil at a depth of about half an inch. Expect germination within 7 to 14 days once conditions are right.
Space plants 4 to 6 inches apart to ensure proper bulb development without overcrowding. These onions do not require support or trellising as they grow low to the ground. Maintain consistent moisture by providing 1 to 1.5 inches of water weekly, and apply a light mulch to retain soil humidity while feeding regularly during active growth.
Watch for onion maggots, thrips, and cutworms, treating with organic controls if needed. Prevent downy mildew, purple blotch, and neck rot by ensuring good air circulation and avoiding overhead watering. Harvest bulbs when they reach maturity, typically 100 to 110 days after sowing, once the tops begin to yellow and fall over.
When to Plant Candy Onion
Planting windows vary by USDA hardiness zone. Look up yours by ZIP code.
| Zone | Start Indoors | Direct Sow | Harvest |
|---|---|---|---|
| Zone 1 | — | June – July | September |
| Zone 2 | — | May – July | September |
| Zone 3 | — | May – June | August – October |
| Zone 4 | — | April – June | August – October |
| Zone 5 | — | April – May | July – November |
| Zone 6 | — | April – May | July – November |
| Zone 7 | — | March – May | July – November |
| Zone 8 | — | March – April | June – December |
| Zone 9 | — | February – March | May – December |
| Zone 10 | — | January – March | May – December |
| Zone 11 | — | January – February | April – December |
| Zone 12 | — | January – February | April – December |
| Zone 13 | — | January – February | April – December |
Companion Plants for Candy Onion
✓ Good companions
Onions repel cabbage worms, flea beetles, and other brassica pests
Onions repel carrot flies while carrots help break up soil for onion bulb development
Onions repel cucumber beetles and other pests while not competing for nutrients
Onions provide natural pest protection while lettuce acts as a living mulch
Onions deter aphids and other soft-bodied insects that attack pepper plants
Onions help prevent black spot and aphid infestations on roses
Onions repel slugs and aphids that commonly damage strawberry plants
Onions deter aphids, spider mites, and hornworms from tomato plants
✗ Keep away from
Both compete for similar soil nutrients and onions can inhibit asparagus spear production
Onions can inhibit nitrogen fixation and stunt the growth of bean plants
Onions release compounds that can reduce pea plant growth and pod development
Nutrition Facts
Per 100g serving (USDA FoodData Central)
