Type
long-day sweet
Onion variety
Yellow Sweet Spanish Onion
A classic large yellow onion with mild flavor and big bulbs under long-day conditions. It is grown more for size and fresh use than long storage.
Days to maturity
110 to 120
Best for
slicing, large bulbs
About Yellow Sweet Spanish
Yellow Sweet Spanish is a long-day heirloom-type onion known for very large, round to globe-shaped bulbs with golden-yellow skin. The flesh is white, mild, and sweet, making it a popular choice for slicing, grilling, and fresh use in northern gardens. Plants are vigorous and can reach jumbo size under good conditions.
Growing Yellow Sweet Spanish Onion
Give it a long growing season by starting seed indoors early or setting out transplants as soon as soil can be worked, spacing bulbs about 4 to 5 inches apart to size up. Consistent moisture and rich, loose soil encourage large bulbs, while crowding will limit size. It offers only moderate storage, so cure the bulbs well after the tops fall and use the largest ones first.
Full growing guide
For planting dates, care, and harvest that apply to all onions, see the complete guide.
How to grow OnionsOther onions varieties
Variety characteristics are general guidance for US home gardens; performance varies by climate, soil, and season. Seed and plant availability differs by supplier. Page updated Aug 4, 2026.