Quick facts
- You can direct seed scallions or grow them from transplants.
- Another green onion that only gardeners can enjoy is the Egyptian walking onion.
- Always start walking onions from the topset bulbs.
- Early in the season, weeds can easily outcompete small scallion plants.
- Pull scallions when they have reached usable size.
- Beginning in the second season, cut walking onion greens as you would chives.
Scallions (Allium fistulosum), also called bunching onions and green onions, have green and white stalks that do not form bulbs. You can chop and eat them as a raw condiment on top of soups and other cooked foods. In Asian cooking, chopped green onions are one of the last ingredients added in stir-fries, briefly cooked before serving. You may also chop and toss them in a salad, or grill them whole as a side dish.
Another type of green onion that home gardeners can enjoy is the Egyptian walking onion, sometimes called a “tree onion” (Allium cepa var. proliferum).
All onions require full sun for best growth.
Planting
- Direct seed as soon as the soil is workable.
- Sow seeds in a two-inch wide band, one-fourth to one-half inch deep, in rows 12 to 18 inches apart.
- After seedlings emerge, thin to one plant every inch.
- Plant seed indoors four weeks before planting outside. For an early May transplant, plant seeds in early April.
- Sow seeds one-fourth to one-half inch deep, and keep evenly moist.
- When ready to transplant, prepare a narrow furrow, or trench, about two inches deep.
- Loosen plants so you can separate them.
- Trim roots to one-half inch and tops to four inches in length.
- Place the transplants in the furrow one inch apart, and fill the furrow with soil.
- Water well.
Another type of green onion that home gardeners can enjoy is the Egyptian walking onion, sometimes called a “tree onion” (Allium cepa var. proliferum).
In late summer, walking onion plants send up a flower stalk. Instead of a blossom, they produce a clump of half-inch diameter bulbs, called “topsets.” When the clump becomes heavy, the stalk collapses, and the topset bulbs form roots where they land, or where a gardener places them.
Walking onions have edible leaves, used as scallions. The small topsets are edible as well, as are the underground bulbs. They both have true onion flavor. If you dig up the bulbs, the plant will not regrow.
Always start walking onions from the topset bulbs, rather than from seeds. Some seed companies carry walking onions. In late summer, when a friend’s plant tips over, you can harvest some bulbs to start your own patch. Choose a sunny spot, perhaps in an herb garden, where the plant can grow undisturbed.
- Plant the bulbs as soon as the topsets are available.
- Press the bulbs into prepared soil with the point up, about one to two inches deep. Space the bulbs six inches apart.
- Cover lightly with straw for winter.
- In spring, you should see small green shoots coming up.
- Weed and water, but do not harvest green onions the first season. Allow the plant to establish itself.
- Once the plants start to produce topsets, you may have to control the spread of the plant. If you allow the topset bulbs to grow wherever they fall to the ground, they will take up a larger area every year.
How to keep your scallions healthy and productive
- If the planting does not receive one inch of rain each week, soak the soil thoroughly at least once a week.
- If your soil is sandy, it is important to water more often than once a week.
- An inch of water will wet a sandy soil to a depth of ten inches, a heavy clay soil to six inches.
- Use a trowel to see how far down the soil is wet. If it is only an inch or two, keep the water running.
- Early in the season, weeds can easily outcompete small scallion plants.
- Weed gently and frequently to keep the planting weed-free.
- Later in the season, the scallions will have formed a dense enough stand that weeds will not be such a problem.
- Weed the walking onion patch regularly as well. Perennial weeds such as quackgrass can be a problem in perennial plantings.
Pull scallions when they have reached usable size. You may need to loosen the soil with a trowel before pulling, to avoid breaking the plant off at the soil line.
Beginning in the second season, cut walking onion greens as you would chives. The plants will send up new leaves.
Managing pests and diseases
Many things can affect scallion roots and stalks. Changes in physical appearance and plant health can be caused by the environment, plant diseases, insects and wildlife. In order to address what you’re seeing, it is important to make a correct diagnosis.
You can find additional help identifying common pest problems by using the online diagnostic tools What insect is this? and What's wrong with my plant? or by sending a sample to the UMN Plant Disease Diagnostic Clinic. You can use Ask a Master Gardener to share pictures and get input.
- Onion maggot bores into plant stems, causing the plants to turn yellow and wilt.
- Many of the same cultural practices help prevent a wide variety of scallions and Egyption walking onion diseases.
- Several kinds of rot can infect scallions and Egyptian walking onions, including Fusarium basal rot, Botrytis neck rot and bacterial soft rot.
Reviewed in 2022