Allium cepa 'Yellow Sweet Spanish'
vegetableA large, mild, all-purpose yellow storage onion: the backbone of most savory cooking worldwide. Milder than white onions when raw, it becomes rich and sweet when cooked. A sweet, long-day onion that, well cured, keeps a moderate 2 to 4 months - sweet Spanish types are mild and are not long-storage onions. Spanish onions refer to the largest, mildest yellow types.
Sun
full sun
Water
Every 3 days
Harvest
~110 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
Nitrogen-rich fertilizer at planting and when tops reach 6 to 8 inches; stop feeding once bulbs begin to swell
Fertilizer
High-nitrogen fertilizer early; balanced formula as bulbs form
Start from transplants or sets for best results. Onions need the right day-length for bulbing. Match long-day varieties to northern gardens and short-day to southern; Yellow Sweet Spanish is a long-day type best grown in the North. Plant 4 to 6 weeks before last frost date. Consistent weed control is critical. Onions compete poorly with weeds. When tops fall over naturally, stop watering and allow bulbs to begin curing in the ground.
Start seeds indoors
Feb 4
Transplant outdoors
Mar 18
Projected first harvest
Jul 6
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; crop rotation annually
Reflective silver mulch; spinosad spray if severe
Cure thoroughly after harvest; store only fully dry bulbs
8-year rotation if detected; never replant alliums in infected soil
Harvest when about half the tops have naturally fallen over; waiting much longer shortens storage life. Gently loosen bulbs with a fork and pull carefully. Cure in a warm (75 to 85 F), dry, well-ventilated location for 3 to 4 weeks. Skin should be fully papery and the neck completely dry before storage. Store in mesh bags in a cold (near 32 F), dry, dark place - onions sprout above 40 F - and expect about 2 to 4 months for this sweet type.
Good source of vitamin C, B6, folate, and quercetin antioxidant. Sulfur compounds have documented antimicrobial and cardiovascular-protective properties. As a sweet onion it is relatively low in sulfur, which makes it mild and sweet but also a shorter keeper than pungent storage onions.
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.