Seeds or Sets?

  • Onions are a biennial plant, taking two years to complete their life cycle. In the first year, an onion will grow from a seed into a plant, forming a bulb and then going dormant for the winter. In their second year, onions will use the energy from the bulb to grow into a plant and flower - creating seeds.

  • Onion sets are onions that have been allowed to grow from seed, and then have been harvested prematurely and dried to give gardeners a jump-start on growing.

  • Onion sets become established and grow more quickly than onions from seed, however the bulbs can have a shorter storage life

  • Here at Avalow, we prefer onion sets for their reliability, but we are excited to be testing sets and seeds in our Show Garden this year!


Planting and Maintenance

  • Create a small row (about 2” deep) with your finger the length you want your onions to grow.

  • Sow one bulb every 6” ending up with 9 onions per row across the length of your Avalow bed.

  • Carefully fill in the row with soil and gently press down.

  • Using a watering can with a breaker, or a hose with a shower head, gently water the area you have planted.

  • Helpful hint: If you are using a hose, use your hand at the end to control the flow and pressure. Water gently to avoid disturbing the bulbs.

  • Maintain moisture in the top layer of soil until you see the first new leaves.

Tip: Refer to your Fall bed maps for suggested onion locations.



  • Spring onions are ready to harvest in around 85 days from the planting date when planting from sets, however they can be harvested at any point during the winter to enjoy as “green onions”

  • Onions planted in the Fall/Winter will yield smaller bulbs than onions planted in the spring, and are best used in their entirety - onion tops and all!

  • Onions will need to be harvested before the weather warms significantly in the spring - a signal to the plants to begin flowering.

Preparation ~ Know Your Onions!

Have you ever wondered why onions make you cry? Onions are full of compounds called sulfoxides that turn into a gaseous form of Sulfenic acid when onions are sliced and the cell walls are broken.

  • A dull knife will break more cell walls in an onion than a sharp knife. Keeping your knives sharp can reduce the tears you shed while slicing onions!

  • The chemical reaction that produces Sulfenic acid happens more slowly when at cooler temperatures. Storing onions in the refrigerator will reduce the amount of gas released.