White Sweet Spanish Onion is a long-day variety of onion that has a large 3-6-inch-diameter size, white globe-shape and crisp, tender white flesh that offers a deliciously mild and sweet flavor. These onions grow to a perfect size, making them ideal for everything from slicing into fresh salads and sandwiches to caramelizing for soups and sauces. Their unique sweetness is perfect for cooking without the overpowering bite of traditional onions, making them a favorite in both raw and cooked dishes. These onions are prized for their impressive storage capabilities, lasting for months in cool, dry conditions, so you can enjoy them long after the harvest season. White Sweet Spanish Onions is easy to grow in a variety of soil types, and their impressive resistance to pests and diseases ensures a healthy, thriving crop with minimal maintenance. Rich in antioxidants and vitamin C, they not only enhance the flavor of your meals but also contribute to a healthy diet.

Also Known As: Long Day Onion, White Spanish Onion, White Globe Onion, Sweet Spanish Onion, Spanish White Onion, White Bulb Onion, Mild White Onion, Sweet White Onion.

Plant Name:	Onion, White Sweet Spanish
Latin Name:	Allium cepa
Days to Germinate:	7-14
Days to Harvest:	120 (Spring Planting) - 270 (Fall Planting)
Plant Height:	1 - 2 Feet
Spread:	6 - 12 Inches
Growth Habit:	Bulbous, Long Day
USDA Zones:	3-6
Lifespan:	Biennial
Brand:	TomorrowSeeds
Sunlight:	Full Sun, Partial Shade
Pollination:	Heirloom, Open-Pollinated
GMO:	No
Fungicide-Treated Seeds*:	No
Seeds Packed For**:	2026

*Fungicide-treated seeds protect the seedlings from diseases until they are up and growing. Do not eat treated seeds.
**Seeds are freshly packed for the growing season of the year listed. Seeds are still viable beyond pack date. Store in a cool and dry location such as the refrigerator or basement to best preserve germination rates.

Planting Instructions:

Soil Preparation:

Choose an area with heavy, well-draining soil that receives at least 6 hours of sunlight each day. Remove weeds, large rocks, and litter from the planting area. Leave small weeds and dead grass, they will enrich the soil when turned under. Spade or till the soil 8-12 inches deep. Loosening the soil will help the plant establish strong roots.

Plants grow best in soil with lots of organic matter. You may optionally add fertilizer or organic material such as compost, leaves, or rotted hay to mix into the soil at this point. For small gardens, scatter 2-3 tablespoons of fertilizer evenly and work into the top 2-3 inches of soil for each hill or 2 foot by 2 foot planting area. For larger gardens, scatter 2-3 pounds of a complete fertilizer for each 100 square feet of planting area. Work fertilizer or organic material into the soil and leave the surface smooth.

Form rows of soil beds 4-6 inches high and at least 6 inches apart. This formation of ridges will help with drainage.

Planting:

Day-Length: Onions form bulbs in response to daylight hours. Since different onion varieties require specific day lengths to trigger bulbing, choose varieties that are suited to your region. Short-day onions are best for southern regions, Intermediate-day onions are day-neutral and can grow well in a wide range of climates, and Long-day onions are suited for northern regions.

Onions grow best in temperatures between 55F - 75F. They can tolerate cooler temperatures during early growth but require warmer conditions as they develop bulbs. Plant onions in the spring as soon as the soil can be worked, about 2-4 weeks before the last frost in spring. Optionally, start onion seeds indoors 10-16 weeks before the last frost in Spring. Harden off, then gently separate the seedlings 4 inches apart and transplant outdoors when the soil reaches 55F. For fall planting to overwinter and harvest in the spring, direct sow seeds outdoors 8-10 weeks before the first frost. Applying mulch or fabric, or planting in beds,cold frames, or low tunnels is strongly recommended if overwintering to prevent bolting in the spring.

To plant, make holes 1/4 inch deep and spaced 4 inches apart down the rows of raised beds. Plant 1-3 seeds per hole. Cover seeds thinly with soil and water after planting. If choosing to thin to the strongest plant, determine the strongest and healthiest plant, then remove all other plants, narrowing to a single plant per hole. Or, broadcast seeds and separate seedlings to the desired spacing when they come up. If growing for green onions and you want a continuous supply throughout the fall, you can sow seeds every 2-3 weeks.

Planting Depth:	1/4 inch
Within-Row Spacing:	4 inches
Between-Row Spacing:	6-12 inches

Care During the Season:

Watering: Water the plants deeply, soaking the soil to a depth of 6-8 inches, once a week. If there is no rainfall or weather is dry and windy, water 2 times a week. Sandy soils may need to be watered more often than heavy clay soils.

Weeding: Keeping plants weed-free improves production. If plowing or hoeing, do not dig to deeply to prevent from cutting the feeder roots.

Fertilizing: Once onion plants have 5-6 leaves, you may optionally apply a complete fertilizer, without letting the fertilizer touch the plants. Use about a 1/2 cup of fertilizer for each 10 feet of onion row. Scatter the fertilizer evenly between the rows around the plants then water the onions. Each leaf on an onion plant forms a ring in the bulb, so more leaves result in more rings and a larger bulb.

Insecticides: Onions have few insect problems, but insecticides may be used to protect plants. Bt-based insecticides and sulfur are organic options that can be used for prevention. Sulfur also has fungicidal properties and helps in controlling many diseases. Before using a pesticide, read the label and follow cautions, warnings and directions.

Diseases: If spots or mold appear, treat plants with an approved fungicide. Neem oil, sulfur, and other fungicides may be used. When using fungicides always follow label directions.

Harvesting:

Onions seeded in spring can be harvested in late-summer to early fall, while onions seeds in fall are ready to be harvested in summer of the following year. Dry bulb onions are ready to harvest when the main stem gets weak and falls over, and at least half of the leaves brown and die back. Once tops have fully collapsed, stop watering and allow the bulbs to dry in the soil for a few days if the weather is dry. Pull the plants out of the soil and cure the onions by leaving them out in the sun or laying them in a warm, dry, well-ventilated area for 2-3 weeks until the outer skins are papery and the necks are fully dry. Once cured, trim the tops and roots, let them keep drying in baskets or boxes and store them in a cool, dry, airy place. If growing for green onions, harvest as soon as they are pencil sized and until they begin to form bulbs.