How to Grow Stuttgart
Allium cepa 'Stuttgart'
Stuttgart is an heirloom onion variety prized for its reliable yield and good disease resistance. Gardeners value this cool-season crop for its ability to tolerate light frost while producing flavorful bulbs suitable for storage.
📷 Wikipedia: OnionStarting Stuttgart: indoors or direct sow?
🏠 Start indoors 4 weeks before your last spring frost, then move the seedlings outside.
If starting indoors, harden off seedlings gradually before transplanting them outdoors once the soil has warmed sufficiently in early spring.
Soil, care & harvest
Prepare loose, well-draining soil with a pH between 6.0 and 7.0. As a cool-season crop, sow seeds indoors or direct-sow them 2 to 6 weeks before your last spring frost date. Press seeds gently into the soil at a depth of about one-third their width, as they require light for germination. Expect sprouts in seven to fourteen days.
Space plants four to six inches apart once seedlings emerge to ensure proper bulb development. These onions do not need support or trellising. Provide one inch of water weekly, reducing frequency as bulbs mature to prevent rot. Apply a light mulch after establishment to retain moisture and suppress weeds.
Watch for onion maggots, thrips, and aphids, which can be managed with row covers or insecticidal soap. Monitor for purple blotch, downy mildew, and white rot; ensure good airflow and avoid overhead watering to prevent fungal issues. Harvest bulbs 110 to 120 days after sowing when they begin to yellow and fall over.
When to Plant Stuttgart
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 | August – 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 Stuttgart
✓ Good companions
Onions repel cabbage family pests including cabbage root fly and aphids
Onions repel cabbage worms, cabbage loopers, and flea beetles
Alliums repel carrot flies while carrots help break up soil for onion bulb development
Onions provide pest protection without competing for nutrients, complementary root depths
Alliums deter aphids and spider mites that commonly attack pepper plants
Onions help prevent black spot and repel aphids, Japanese beetles, and other rose pests
Onions deter slugs, aphids, and other soft-bodied pests that damage strawberry plants
Onions deter tomato hornworms and aphids while improving tomato flavor
✗ Keep away from
Onions may inhibit asparagus growth and can compete for similar soil nutrients
Onions can inhibit bean growth and nitrogen fixation by rhizobia bacteria
Alliums can stunt pea growth and interfere with their nitrogen-fixing capability
Nutrition Facts
Per 100g serving (USDA FoodData Central)
