How to Grow Texas Sweet Onion
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Texas Sweet Onion
Allium cepa var. cepa
vegetableTexas Sweet is a large, mild, sweet onion variety known for its tender flesh and low pungency. These long-day onions are primarily grown in Texas and other warm regions, forming large, globe-shaped bulbs with golden-brown papery skin. They are prized for fresh eating, cooking, and their exceptional sweetness compared to standard storage onions.
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Example Texas Sweet Onion timeline · Pittsburgh, PA (Zone 6b)
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Plant Texas Sweet 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 Texas Sweet Onion
Around Jul 26≈ 100 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Texas Sweet Onion dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Best in zones 8-10; can be grown in zone 7 with careful timing
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Seedling/Transplant
2-4 weeksSmall green shoots emerge with thin, grass-like foliage. Roots establish within 1-2 weeks.
Keep soil consistently moist but not waterlogged. Provide bright light to prevent leggy growth. Plant transplants 4-6 weeks before last frost in spring or in fall for best results.
Vegetative Growth
6-8 weeksFoliage expands with multiple green leaves reaching 12-18 inches tall. No visible bulb formation yet.
Maintain consistent watering and fertilize every 3-4 weeks with balanced or nitrogen-rich fertilizer. Mulch around plants to retain moisture and suppress weeds. Thin to proper spacing if needed.
Bulb Development
4-6 weeksBase of plant swells underground as bulb begins to form and enlarge. Foliage continues growing but less vigorously.
Maintain regular watering. Switch to phosphorus-rich fertilizer to encourage bulb development. Remove any flower stalks that emerge (bolting). Keep area weed-free to reduce competition.
Bulb Maturation
2-3 weeksBulb reaches full size, becoming visible at soil surface. Outer papery layers form. Foliage yellows and begins to topple over naturally.
Reduce watering as tops yellow; this signals bulb dormancy. Do not force tops over; let nature take its course. Stop fertilizing. Leave in ground until 80% of tops have fallen over.
Harvest & Curing
2-3 weeks curingTops are completely dry and brown. Bulbs are firm with papery, golden-brown skin.
Harvest when tops are fully dried. Cure in a warm, dry, well-ventilated location for 2-3 weeks before storage. Store in cool (40-50°F), low-humidity conditions for extended shelf life.
Common Pests
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Use row covers over young plants, remove affected plants immediately, rotate crops yearly, apply neem oil or spinosad if needed
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Spray with insecticidal soap or neem oil, maintain consistent moisture to reduce stress, remove weeds that harbor thrips
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Use disease-free sets/transplants, ensure excellent drainage, do not overwater, practice 3-4 year crop rotation, remove affected bulbs immediately
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Improve air circulation, avoid overhead watering, apply copper or sulfur fungicides, remove infected foliage
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Avoid overhead watering, ensure good drainage, apply copper fungicides, remove lower infected leaves
Uses
Fresh eating and salads
CulinaryTexas Sweet onions are exceptionally mild and sweet, making them ideal for eating raw in salads, on sandwiches, and as crudités. Their low sulfur content means they lack the harsh bite of storage onions. [source]
Grilling and caramelizing
CulinaryThe natural sugars in Texas Sweet onions make them excellent for grilling whole, slicing for fajitas, or slowly caramelizing for soups and sauces. They develop rich, sweet flavors when cooked slowly. [source]
Pickling and preservation
CulinaryTheir mild flavor and crisp texture make Texas Sweet onions excellent candidates for pickling, relishes, and canning. They add sweetness without overpowering other ingredients. [source]
Nutritional and anti-inflammatory benefits
MedicinalOnions contain quercetin, an antioxidant with anti-inflammatory properties, as well as vitamins C and B6, and sulfur compounds that support immune health and cardiovascular function. [source]
Storage and versatile ingredient
HouseholdWhile not as long-storing as yellow onions, Texas Sweet onions keep 3-4 months in proper conditions and are a staple pantry ingredient for year-round cooking. [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 in late spring/early summer when 70-80% of tops have dried and fallen over. Gently loosen soil and pull bulbs by hand. Cure in a warm (75-85°F), dry, well-ventilated space for 2-3 weeks until outer papery layers are completely dry. Store in mesh bags or braids in cool (40-50°F), low-humidity conditions; they store for 3-4 months but are best eaten within 2-3 months due to their sweet nature and reduced storage life compared to pungent varieties.
Fun Facts
- 🌱 Texas Sweet onions are a long-day variety that requires 14+ hours of daylight to bulb properly, which is why they thrive in Texas and other southern regions during spring planting.
- 🌱 The sweetness of Texas onions comes from their low sulfur content (1015 variety has even lower sulfur than standard varieties), which produces fewer pungent compounds during digestion.
- 🌱 Texas Sweet onions received their name and popularity in the 1980s-1990s but were originally developed from 1015Y and other Southern varieties bred specifically for warm climates and sweet flavor.
Gardening Terms
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