Here are answers to some of the most common questions we receive about garden plants. You will find concise information on general gardening techniques as well as plant selection and care. For detailed information on specific plant pests and problems refer to our Common Garden Pests and Problems page.

Do you have additional gardening questions? Please contact us. Here's how.

Horticulture Questions and Answers

Home  >  Vegetables and Herbs  >  Selection, Culture and Care  >  How do I grow onions?

How do I grow onions?

No home garden is complete without onions. They are easy to grow and take little space. One of the most useful onions for the small garden is the perennial top multiplier. Once established it grows for many years and produces tasty green onions throughout the growing season.

You can start top multiplier onions from seeds, topsets or you can lift and reset a clump of plants. Once you establish them, remove and plant the top sets each fall around mid October for new green onions early the following spring.

Onion sets are planted in early spring. These can be harvested as green onions in late spring or as bulb onions during late summer and fall. Harvest as soon as the tops fall over. Cure and keep onions in a cool dry place. Bulb onions from sets generally don't store well.

Onion seeds may be sown directly in the garden in early spring. Thin seedlings to 6 or less per square foot or 4 inches apart in rows. Pull the bulbs with the tops on as soon as the tops fall over. Do not break over the green tops. Cure them with the tops on for two to three weeks. Once the tops are dry, cut them off one inch from the bulb. Cure the bulb for another 2 to 3 weeks before you store them in a cold dry place.

Many home gardeners also grow a few short rows of a mild flavored sweet spanish onion for sandwiches, salads, fried onion rings and buttered onion rings. A good selection is Burpee sweet spanish hybrid. Start seeds for these onions inside around February 15th in a small box or tray filled with a disease free growing mixture. After the seedlings get to be five inches tall, keep them clipped back to 4 inches so that they will remain upright. Transplant seedlings to the garden around April 15 with plants at least 4 inches apart in the row and with 18 inches between rows. Harvest bulbs with the tops on and cure for 2 weeks. Then, cut the tops to one inch or so from the bulb and cure for another 2 or 3 weeks before storing in a cold dry place.