VegetableOnion
White Sweet Spanish Onion
White Onion
White Sweet Spanish Onion delivers impressive bulbs over 3 inches across with glistening white skins and remarkably mild, sweet flesh that makes it a kitchen favorite. Hardy across zones 2-9, this long-day onion matures in 110-120 days into towering plants reaching up to 24 inches tall. Unlike its sharper yellow cousin, this variety brings gentle onion flavor perfect for delicate dishes where you want onion presence without overwhelming heat.
Photo © True Leaf Market
Growing Conditions
USDA Zone
2-9
Sunlight
Full Sun
Water
Moderate
Soil
Well-drained, Fertile Loam, Moderately Rich
Preferred Temp50-75°F
Growth Stats
24 in
Height
—
Width
3 in
Spacing
110–110
Days to Harvest
PeriodBiennial (Grown As Annual)
TypeBulbing - Long Day
Plant Profile
Sunlight
Full Sun
Water
Moderate
Zones
2-9
Size
24in H x ?in W
Growth
Biennial (Grown As Annual)
Care
Moderate
Hover over chart points for details
Highlights
These spectacular onions grow into large, glistening white bulbs prized by cooks for their easy-to-peel skins and remarkably sweet, mild flavor. The White Sweet Spanish stands apart from the more common yellow variety by offering all the size and storage capability with notably less bite. Kitchen gardeners love how these substantial bulbs add gentle onion character to cream sauces and light broths without overpowering delicate flavors.
Common Uses
White Sweet Spanish Onions excel in dishes requiring gentle onion flavor, particularly cream sauces and light broths where their mildness won't overpower delicate ingredients. Their large size and easy-to-peel skins make them ideal for cooking applications that benefit from substantial onion presence without sharpness. The green stalks can also be harvested as scallions while the bulbs are developing.
Growing Timeline
First Bloom
Not Applicable (Harvested Before Flowering)
First Harvest
100-120 Days After Planting
Last Harvest
Determinate
Care Instructions
Direct Sow
Plant in spring when soil temperatures reach 60-75°F in northern gardens, or in fall for southern regions. Space seeds 3 inches apart in rows 15 inches wide.
Harvesting
Harvest when the upright green stalks begin to fall over and turn yellow, typically after 110-120 days. The bulbs will have reached over 3 inches in diameter and developed their characteristic glistening white skins. Scallions can be harvested from the green tops as the onions approach maturity.
Growing Calendar
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Companion Planting
Ecology & Traits
Edible
Scientific Classification
Allium L.
Family
Amaryllidaceae
Genus
Allium
Duration
Biennial (Grown As Annual)
Native Status
L48 (I)