Allium cepa 'White Sweet Spanish'
vegetableA mild, low-sulfur sweet onion excellent for raw use in salads, sandwiches, and guacamole. White onions are a staple of Mexican, Latin American, and Southwestern cooking. Less pungent than yellow onions, they have a brighter, cleaner flavor and a shorter storage life than storage varieties.
Sun
full sun
Water
Every 3 days
Harvest
~100 days
Difficulty
easy
Lifecycle
biennial
Leaves year 1, flowers year 2
Spacing
4-6 in
Planting Depth
1/2-1 in (sets or transplants)
Soil pH
6.0-7.0
Soil Type
Loose, well-draining
Hardiness Zones
Zones 3 – 10
Grown as an annual — this range is its winter hardiness, but you can grow it for a single season in any zone.
When to Fertilize
At planting; nitrogen side-dress once tops reach 6 inches
Fertilizer
High-nitrogen fertilizer early; balanced formula as bulbs begin to swell
Grow from transplants or sets for the most reliable results. Plant 4 to 6 weeks before last frost — onions are cold-hardy. Choose appropriate-length-day varieties for your latitude. Long-day onions (14+ hours) suit the North; short-day varieties (10 to 12 hours) suit the South. Keep beds weed-free as onions compete poorly with weeds. Stop watering once tops begin to fall over naturally to begin bulb curing.
Start seeds indoors
Feb 4
Transplant outdoors
Mar 18
Projected first harvest
Jun 26
Good neighbors that attract beneficial insects or deter pests
Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide
Row cover from planting; avoid fresh manure before planting; rotate crops annually
Reflective mulch deters thrips; spinosad spray if severe
Plant in raised beds with good drainage; avoid overhead watering; copper fungicide
Strict rotation; do not plant alliums in same bed for 8+ years if affected
Harvest when 50 to 75 percent of tops have naturally fallen over. Carefully lift with a fork. Cure in a warm, dry, well-ventilated spot for 2 to 3 weeks until papery skin forms and necks dry out completely. White onions store 1 to 2 months — significantly less than yellow storage onions. Use early in the season.
Good source of vitamin C, vitamin B6, folate, and quercetin. Contains sulfur compounds with documented antimicrobial properties. Lower in sulfur compounds than yellow onions, making them more digestible for some people.
For educational and informational purposes only — HomeSown is not medical, health, or other professional advice. Always positively identify any plant before handling or eating it; some plants, and some parts of otherwise-edible plants, are toxic. Consult a qualified professional before consuming or otherwise using any plant, especially if you are pregnant, nursing, taking medication, or have a health condition.