How to Grow Catawissa Onion
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Catawissa Onion
Allium cepa var. cepa
vegetableCatawissa is a heirloom yellow storage onion prized for its exceptional keeping quality and sweet flavor. This variety produces large, golden-brown bulbs with a flattened shape and is known for storing 8-10 months or longer without sprouting. It's a reliable, productive onion well-suited to long-season growing regions.
When should you plant Catawissa Onion in your zone?
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Example Catawissa Onion timeline · Pittsburgh, PA (Zone 6b)
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Plant Catawissa 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 Catawissa Onion
Around Aug 15≈ 120 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Catawissa Onion dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-8; performs best in northern climates with long growing seasons (120+ days)
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Get my Catawissa Onion timeline →Growth Stages
Seedling
2-3 weeksThin green shoots emerge; plant develops first true leaves resembling grass
Keep soil consistently moist but not waterlogged; maintain steady warmth (60-70°F); thin to proper spacing early
Vegetative Growth
6-8 weeksMultiple upright leaves develop; plant energy focuses on building a strong root system and leaf biomass
Maintain consistent watering and regular feeding; side-dress with nitrogen every 3-4 weeks; ensure adequate sunlight; remove flower scapes if they appear
Bulbing
4-6 weeksBase of plant begins to swell as photoperiod and day length trigger bulb formation; leaves continue to elongate
Reduce nitrogen fertilizer; increase potassium and phosphorus to support bulb development; continue consistent watering; avoid excess nitrogen which delays bulbing
Maturation
3-4 weeksBulb swells noticeably; outer scales thicken and papery layers form; leaves begin to yellow and soften at base
Gradually reduce watering; withhold fertilizer; allow tops to yellow naturally; do not break over tops prematurely
Harvest & Curing
2-3 weeks curingTops dry and fall over naturally; bulbs reach full size with papery golden-brown skin; neck seals
Pull or dig when 50-75% of tops have fallen; cure in warm, dry, well-ventilated space for 2-3 weeks before storage; brush off soil gently but do not wash
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Use floating row covers at planting; apply beneficial nematodes to soil; remove infested plants; encourage predatory insects
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Spray neem oil or insecticidal soap; introduce predatory mites; thin plants for better air circulation
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Practice crop rotation (5+ year cycle); avoid overhead watering; remove and destroy infected plants and surrounding soil; improve drainage
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Use resistant varieties; practice strict crop rotation; improve soil drainage and air circulation; sterilize tools
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Ensure good air circulation; avoid overhead watering; apply copper fungicide if needed; remove infected foliage
Uses
Long-term storage and cooking
CulinaryCatawissa is exceptional for winter storage, providing fresh onions well into spring. Its mild, sweet flavor makes it excellent for soups, stews, roasting, and long-cooked dishes. [source]
Fresh eating and grilling
CulinaryThe sweet, tender flesh is delicious sliced raw in salads or grilled whole. Its low pungency compared to storage onions makes it ideal for those who prefer milder onion flavor. [source]
Food preservation and canning
HouseholdLarge, uniform bulbs are ideal for pickling whole or in slices. The firm flesh maintains quality through the canning process. [source]
Traditional remedies and wellness
MedicinalOnions contain quercetin and other antioxidants believed to support immune function and cardiovascular health in traditional medicine. [source]
Pollinator support
WildlifeIf onions bolt and flower, the delicate blooms attract bees and other pollinators while also providing seeds for future seasons. [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 50-75% of tops have naturally fallen over and dried, typically late August to September in northern regions. Dig bulbs carefully to avoid bruising, which compromises storage. Cure in a warm (70-75°F), dry, well-ventilated location for 2-3 weeks until outer scales are papery and necks are completely sealed. Brush off dried soil gently; do not wash. Store in a cool (45-55°F), dark, dry space with good air circulation; properly cured Catawissa onions keep 8-10 months or longer.
Fun Facts
- 🌱 Catawissa is a true American heirloom variety, developed in the 19th century in the Catawissa Valley of Pennsylvania; it remains one of the finest long-keeping yellow onions available today.
- 🌱 Properly cured Catawissa onions can store for 8-10 months or longer in cool conditions—far longer than many modern hybrid varieties—making them ideal for homesteaders and those practicing food preservation.
- 🌱 The variety's exceptional storage ability is due to its naturally high dry matter content and thick, protective papery outer scales that seal tightly at the neck, preventing moisture loss and pathogen entry.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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