Onion Plants

For those looking to get an early start on spring planting, we have a great selection of onion plants and seeds already in stock.  A good rule of thumb is you can plant onions directly in the garden after St. Patrick’s Day, but with our unpredictable Colorado weather it is important to keep an eye on them. Use mulch, Season Extenders, or row cover to help protect young plants from low temperatures. For planting, choose a very sunny location with 8 hours or more of direct sun per day with fertile soil that drains well. Onions are heavy feeders and benefit greatly from an application of a nitrogen-rich fertilizer such as El Primero Organic Garden Fertilizer (21-4-4) made locally by Alpha One. 

There are three options to grow onions: seeds, sets, and plants. 

  1. Seeds: Onion seeds are available in many varieties and should be planted as soon soil is workable in spring. Harvest them in their first season to enjoy the tastiest onions, or let them overwinter and continue growing a second season to bloom and produce seed for future planting. 
  2. Sets: Small onion bulbs that are harvested before maturity from the first year of an onion’s life cycle and stored through winter. Although sets are easy to find and plant, they often yield smaller onions, making them more well-suited to produce green onions rather than larger bulb onions. Since onions grown with sets are in the second year of their life cycle, they are more likely to bolt, or grow a flower from the center of the bulb.  *We will receive our first shipment of sets later this spring as we get closer to planting season so please call or stop by to check on availability. 
  3. Plants: Onion seedlings that are started in the current growing season and are ready for transplant into your garden. These typically produce larger and juicier bulbs than sets. Plants are preferable to seeds when early spring temperatures are unpredictable. Shop early to find the best available selection and store your onions in a cool, dry environment until you’re ready to plant.

You’ll cry tears of joy after tasting one of these savory onion plant varieties:

  • Highlander Onion: This sweet onion has early maturing bulbs that grow up to 4”. They are easy to cure and store well for up to 5 months.
  • Red Candy Apple Onion: This onion features a large, flattened red globe and is the type of red onion you’ll find in an Italian restaurant or salad bar. There is limited storage capacity with this one.
  • Superstar Onion: This large, white onion has a mild, sweet flavor and stores up to 2 months. It is the only white onion to win All American Selection!
  • Walla Walla Onion: This onion has pale yellow scales with white interior and is the sweetest of the long day varieties. They can be stored for one month.

Originally published on February 2nd, 2024.