How to Grow Purplette
Allium cepa
Purplette is a flavorful heirloom onion variety prized for its mild taste and compact size. Gardeners grow this cool-season allium to enjoy fresh bulbs in salads or cooked dishes while benefiting from its reliable performance across many zones.
📷 Wikipedia: OnionStarting Purplette: indoors or direct sow?
🌾 Sow directly in the garden — Purplette is not usually started indoors.
Direct sow seeds outdoors two to six weeks before the last frost date; do not start indoors as onions generally perform poorly with transplanting.
Soil, care & harvest
Prepare loose, well-draining soil with a pH between 6.0 and 7.0 for optimal growth. Sow seeds directly outdoors two to six weeks before the last spring frost, as onions are cool-season crops that tolerate light freezing temperatures. Press seeds gently into the soil at a depth of about one-quarter inch. Expect germination within seven to fourteen days under these conditions.
Space plants one to two inches apart if direct sowing, or thin seedlings accordingly once they emerge. Provide consistent moisture, aiming for one inch of water per week to maintain light soil dampness without saturation. Apply a layer of mulch around the base to retain moisture and suppress weeds, but avoid piling it against the stems.
Watch for onion thrips, aphids, and cutworms; use row covers or hand-picking to manage these pests early. Prevent purple blotch, downy mildew, and neck rot by ensuring good air circulation and avoiding overhead watering. Harvest the bulbs approximately sixty days after sowing when they reach full size and begin to dry.
When to Plant Purplette
Planting windows vary by USDA hardiness zone. Look up yours by ZIP code.
| Zone | Start Indoors | Direct Sow | Harvest |
|---|---|---|---|
| Zone 1 | — | June – July | August – September |
| Zone 2 | — | May – July | July – September |
| Zone 3 | — | May – June | July – October |
| Zone 4 | — | April – June | June – October |
| Zone 5 | — | April – May | June – November |
| Zone 6 | — | April – May | June – November |
| Zone 7 | — | March – May | May – November |
| Zone 8 | — | March – April | May – December |
| Zone 9 | — | February – March | April – December |
| Zone 10 | — | January – March | March – December |
| Zone 11 | — | January – February | February – December |
| Zone 12 | — | January – February | February – December |
| Zone 13 | — | January – February | February – December |
Companion Plants for Purplette
✓ Good companions
Strong allium scent deters cabbage worms, aphids, and flea beetles
Alliums repel carrot flies and root maggots that damage carrot crops
Alliums provide pest protection without competing for nutrients in shallow soil
Both plants repel similar pests, creating a strong protective barrier in garden beds
Allium compounds repel aphids and may reduce fungal diseases around peppers
Alliums repel aphids, thrips, and other pests that commonly attack roses
Alliums deter slugs, aphids, and nematodes that commonly damage strawberry plants
Alliums deter hornworms and aphids while potentially improving tomato flavor
✗ Keep away from
Alliums can stunt asparagus growth and reduce spear production through root competition
Alliums can inhibit nitrogen fixation by beneficial bacteria in bean root nodules
Allium compounds may interfere with the symbiotic relationship between peas and nitrogen-fixing bact…
Nutrition Facts
Per 100g serving (USDA FoodData Central)
