Onion Seeds

When it comes to growing onions, you want to start with quality seeds to produce the best results. For more than 140 years, Harris Seeds has been one of the most trusted onion seed suppliers for growers and gardeners.

Related Categories

Bunching Onion Seeds

Sweet Spanish Onion Seeds

Red Hybrid Onion Seeds

Onion Transplants

Onion Sets

Organic Onion Seeds

Onion Seeds

Onion Plants Overview

For many growers, onions and leeks are too long of a season crop to grow from seed. Now you can enjoy these flavorful vegetables all summer and into the fall by growing them from transplant.


Give your onions a head start with our onion plants. Use them for scallions or let them mature to large bulbs. All varieties listed are pulled and shipped to you the same day by one of the most reputable onion growers in the U.S.


All orders must be placed before the first week in May. Unfortunately, we can no longer ship onion transplants to Idaho. Approximately 5 dozen (60) plants per bunch.

Average Seed Count:

Bulb Onions: 450 per packet; 7,500 seeds/Oz.

Bunching Onions: 700 per packet; 12,500 seeds/Oz.

Onion Growing Guide

The size of an onion bulb is dependent upon the number and the size of the green leaves (or tops) at the time the bulbing process begins. For each leaf, there will be one ring of onion. The larger the leaf, the larger the ring will be. The triggering of the bulbing process is dependent upon daylength and temperature. Remember that the further north you are, the more hours of daylight you have during the summer.

Onions are a versatile food. We have many onion seeds for sale, including the following bestsellers:

  • Sweet Spanish onions: Most vegetable gardens should include a few rows of sweet Spanish onions. Perfect for eating raw or cooked, this onion has a well-earned reputation for versatility.
  • Red onions: With their crisp intensity, red onions are a cook's and a canner's delight. They add flavor and color to dishes and hold their own against other ingredients. 

White bunching onions: Called spring onions, green onions or scallions, white bunching onions have an appealing taste that makes them ideal for salads and farm-to-table appetizers. Their stalks can be eaten or used as garnishes.

Bunching onions can be directly sown outdoors in early spring, but bulb onions (storage and sweet Spanish types) are best started indoors in February and transplanted to the garden in April. For complete planting instructions, ask for our free Harris Seeds Home Gardening Guide when placing your order. The tall leaves of the bulb onion will begin to bend over when the bulb nears maturity. 


Before harvesting, carefully bend all leaves horizontal to the ground, expose the bulb and let it stay in the ground until the leaves turn brown. Lift bulbs out of ground, cut off leaves to 1-2 above bulb, and hang outside in mesh bags to dry for at least 7 days. To store, lay in ventilated boxes or mesh bags in a cool, dry area. Onions should store several months without loss of quality.


Learn more in our onion growing guide.

Depending on your region of the country, growers that sell at farmers’ markets have many choices. Bunching onions probably have the most marketing appeal when displayed at the market, and bulb onions have had their reputation built by grocery chains and grower associations. Growing sweet Spanish types locally and branding them as locally grown will appeal to consumers.