How to Grow Excel Onion
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Excel Onion
Allium cepa 'Excel'
vegetableExcel is a long-day yellow onion variety bred for exceptional storage capability and disease resistance. It produces medium to large, golden-bronze bulbs with excellent keeping quality, making it ideal for long-term storage without sprouting. This variety is popular with both home gardeners and commercial growers due to its reliability and extended shelf life.
When should you plant Excel Onion in your zone?
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Example Excel Onion timeline · Pittsburgh, PA (Zone 6b)
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Plant Excel Onion
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Excel Onion
Around Jul 26≈ 100 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Excel Onion dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-9; best suited to northern regions with at least 14+ hours of daylight during bulbing season
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Get my Excel Onion timeline →Growth Stages
Seedling/Set Establishment
2-3 weeksSmall green shoots emerge from onion sets or seeds; roots develop into soil.
Keep soil consistently moist but not waterlogged. Thin seedlings to proper spacing if direct seeding. Ensure adequate light to prevent weak, leggy growth.
Vegetative Growth
4-6 weeksFoliage develops with multiple green leaves; plant focuses on leaf and root expansion. Bulb remains small.
Maintain consistent moisture and moderate nitrogen fertility. Monitor for pests and diseases. Provide full sun exposure. Remove any flower scapes if they appear.
Bulbing
4-6 weeksAs day length increases and temperatures warm, the plant redirects energy to bulb formation. Base of plant swells; foliage begins to yellow.
Reduce nitrogen fertilizer to avoid excess leaf growth. Maintain consistent (but not excessive) moisture. Increase daylight exposure is critical for this variety's bulbing response.
Maturation
2-3 weeksBulb reaches full size; outer scales dry and papery. Foliage yellows and begins to fall over (topple).
Reduce watering gradually to help cure the bulb. Do not force tops over; let them fall naturally. Stop fertilizing. Watch soil moisture—too much can cause rot or sprouting.
Harvest & Curing
Harvest occurs over 1-2 weeks; curing takes 2-3 weeksFoliage is mostly brown and dry; bulb is firm with papery skin.
Harvest when 75-80% of tops have fallen over. Cure in a warm, well-ventilated location (70-80°F) for 2-3 weeks before storage. Store in cool (40-50°F), low-humidity conditions.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with neem oil or insecticidal soap; maintain consistent irrigation to reduce stress; reflective mulches can deter adults
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Use row covers over sets; apply beneficial parasitic nematodes (Steinernema carpocapsae) to soil; rotate crop location yearly
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Ensure good air circulation; avoid overhead watering; apply sulfur or copper fungicide if symptoms appear; remove infected foliage
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Plant disease-resistant varieties like Excel; use pathogen-free sets; avoid excess nitrogen; do not overwater; practice crop rotation
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Hand-pick early morning; use pheromone traps; spray with spinosad if damage is severe
Uses
Fresh cooking and storage
CulinaryExcel onions have a mild, slightly sweet flavor suitable for raw eating in salads, grilling, roasting, and sautéing. Their exceptional storage capability makes them ideal for year-round use in the kitchen. [source]
Long-term pantry storage
HouseholdExcel's disease resistance and superior shelf life make it the preferred choice for root cellar and cold storage preservation. Properly cured bulbs remain firm and sprout-free for 5-8 months, providing fresh onions well into winter. [source]
Quercetin and antioxidant benefits
MedicinalYellow onions contain significant amounts of quercetin, a powerful flavonoid with anti-inflammatory and antioxidant properties. Regular consumption may support cardiovascular health and immune function. [source]
Natural dye production
CraftThe dried papery outer scales and inner layers yield golden-yellow and warm brown dyes suitable for wool and plant-based textile dyeing. Onion skin has been traditionally used in natural dye crafts for centuries. [source]
Pollinator attraction during flowering
WildlifeIf allowed to bolt and flower (normally avoided for bulb production), Excel onions produce umbrella-like clusters of small white or pink flowers that attract bees and beneficial insects. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Harvest when 75-80% of foliage has naturally fallen over, typically in late summer. Dig carefully to avoid bruising the bulbs. Cure in a warm (70-80°F), dry, well-ventilated area for 2-3 weeks until the outer skin is papery and the neck is completely dry. Store in mesh bags or braided strands in a cool (40-50°F), dry location. Excel onions can store for 5-8 months under ideal conditions.
Fun Facts
- 🌱 Excel was developed specifically for its resistance to Fusarium basal rot, a disease that plagued earlier onion varieties, making it a game-changer for commercial storage operations.
- 🌱 The name 'Excel' reflects its exceptional shelf life and disease resistance, allowing it to outperform earlier storage varieties by remaining firm and sprout-free for 5-8 months without special equipment.
- 🌱 Excel is classified as a 'long-day' onion, meaning it requires 14+ hours of daylight to trigger bulbing, making it perfectly suited to northern growing regions and less ideal for southern latitudes where day length is shorter.
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