Scallions - SARE

Allium cepa (Alliaceae or onion family)

Production

Soil preparation

Scallions should not follow any members of the allium family or be planted next to garlic due to the presence of overwintering thrips.
Apply compost and other amendments based on the results of a soil test.
Spread lime as needed to increase both the pH and Ca levels. Dolomite lime will also increase Mg levels. Spread gypsum when calcium levels are low but pH is correct.
A fertilizer company can add OMRI-listed potassium sulfate to compost if it doesn’t have enough K to meet the crop’s needs. If this isn’t possible, spread the correct amount of fertilizer and incorporate it before planting.
Most vegetable crops remove little P, but at times your soil test result will call for additional P. Unfortunately, there aren’t short-term options for an organic grower to increase the available P levels in the soil. Through the use of animal-based fertilizers, P will build up to a level in the soil that is sufficient for all vegetable crops.
Incorporate compost and plant scallions in raised beds.

Common recommended fertilizer rates¹

Nitrogen	Phosphorus	Potassium	pH
120	0-200	0-200	6.0-6.4
¹Rates are for New York and are from Cornell University’s Nutrient Guidelines for Commercial Vegetable Production (2019). Check the Cornell website for updated guidelines, or consult with local experts for recommended rates outside New York.

Varieties

Ishikura, Nabechan

Greenhouse guidelines

EZ Seeder seeding plate #9

Cell pack tray	Germination temp	Growth temp	Hardening off	Notes
128	60°–85°	60°–65° daytime; 55°–60° nighttime	Withhold water	7–9 seeds per cell. Take plants outside 1 week before planting in the field.

Number of successions

Scallions can be planted all season, starting in early spring and entering fall. Start with a 14-day interval and reduce each following succession by 1 day until plantings are weekly. In other words, the intervals between plantings will be 12-11-10-9-8-7-7-7. The last seeding is usually in August.

Transplant readiness indicators

Harden plants off outside; plants that are lush don’t perform well in the field.
Plants are ready when they come easily out of their cells.

Transplant tips

You can also transplant scallions using a paper-pot planter, which allows you to get optimum spacing and an early start. Start paper pots in the greenhouse. This results in a high germination rate. Use pot spacing of 2 inches (CP303) for easy picking. Plant when the scallions have developed enough root system to hold onto the pot but not until they start branching out into other pots. Slightly bury the plants and make sure the pots themselves are fully covered to avoid drying out. Irrigate the first week until roots are established.
Using paper pots is also a means to avoid transplant shock, as scallion roots don’t hold the pot together well in a cell pack.

Transplanter

Rows	In-row spacing	Planting depth (inches)	Notes
3	5 inches	Not too deep; the same level as the potting medium and a little below	Use a 5-inch sprocket.

Cultivation procedures

Prepare seed beds 1–2 weeks in advance. If possible, shallowly stale seedbed before planting to eradicate weeds. Don’t disturb the soil too deeply, as this can bring up new weed seeds.
Use a basket weeder or wheel hoe when weeds are in the white thread stage, without burying the young crop. Weed control is more effective when you eliminate weeds before they emerge.
Hand hoe between plants.
Use finger weeders or spring hoes in combination with side knives for a second cultivation. These tools effectively eliminate small weeds.

Frost, disease and insect protection

Watch for onion thrips, and control with a spinosyn-based product, such as Entrust, or Beauveria bassiana, as in the product Mycotrol ESO. With Beauveria bassiana you’ll see results after a week of applying. Alternatively, use a mineral oil like JMS Stylet-Oil. Repeat applications of the selected product every 5–7 days. Don’t exceed the maximum rate of 3 applications per season for Entrust. As direct contact with the pest is required for all these products, only spray at night, as thrips are nocturnal. Act when pest pressure is still low.
Purple blotch (Alternaria porri) occurs mostly in the summer under wet and humid conditions. Plants that are weakened by thrips are more susceptible to this disease. Keeping the crop weed free to allow for air circulation, planting long rotations, practicing good sanitation (e.g., removing or incorporating diseased plant material) and avoiding excessive N are good preventive measures.

Other cultural practices

Irrigate frequently for optimum yield and plant health. Frequency depends on soil type, evaporation, precipitation and the particular needs of the crop.

Double cropping and/or cover cropping

Follow scallions with another short season cash crop like lettuce, spinach, arugula or radishes, or plant a cover crop.

Harvest

Yield	An average of 1 bunch per row foot
Standards	Harvesting¹ 50 bunches per person, per hour, or approximately 300–450 hours per acre
Standards	Washing 100 bunches per person, per hour
Tools and supplies needed	Rubber bands or twist ties (customer preference may influence this), regular 1 ⅓-bushel boxes, and serrated knives. Use a tractor and bedlifter if available.
¹Harvest rates don't include the time required to transport crops from the field to a wash and pack shed or storage facility.

Ready-to-harvest and quality indicators

When scallions are about pencil size to ½ inch in diameter with tops at least 12 inches tall.
Scallions have dark green foliage, aren’t crushed or damaged, and have no signs of any defects from insects, bacterial rot or other pathogens. Roots are pure white.

Harvest procedures

Wash hands and sanitize knives before harvesting.
Harvest in the morning hours to avoid field heat accumulation.
Pull scallions out by grabbing them as low as possible at the stem to avoid crushing the green part of the stem. If possible, precede harvest with a bedlifter.
Each bunch contains about 6–8 scallions, weighing about 4 oz. If needed, clean off any yellow leaves before placing a rubber band or twist tie around the bunch. Make sure all scallions are even at the root base.
Shake some of the soil particles off the roots and cut them at approximately ½ inch with a serrated knife.
Don’t count and box the bunches as you make them. Instead, place 4 or 5 bunches in a pile. When there are quite a few piles on the ground, someone can pick them up and count them into plastic harvest boxes, placing either 24 or 48 bunches in each harvest box.

Washing procedures

Wash hands and rinse boots before entering the wash-and-pack shed, and cover up field clothes with a bib. If a long-sleeve shirt contains soil, remove this as well.
Place scallions on a wire mesh table and rinse them off by hand, but don’t dump them into a washing tub, as waterlogged scallions will rot easily. Some growers have connected a valve operated by a foot pedal to a stationary nozzle to free up a hand, which increases efficiency.
Alternatively, run scallions through a rinse conveyor washer, and make sure you use the appropriate pressure on the nozzles to avoid crop damage. Add a sanitizer like hydrogen peroxide and peracetic acid to the water in the circulation tank of the rinse conveyor vegetable washer. Use the guide How to Wash Produce Using a Peracetic Acid Solution to establish how much sanitizer solution to add to water.

Additional resources

Packing and storage summary for scallions

Cleaning in field	Remove yellow leaves. Cut roots at ½ inch. Leaves are cut to the length of the box if needed (this isn’t preferred).
Packing in the field	24 or 48 bunches to a regular 1 ⅓-bushel box
Packing for delivery	24 or 48 bunches to a regular ½ or 1 ⅑-bushel box weighing approximately 5–6 lbs. or 10–12 lbs. See the International Federation for Produce Standards for the correct PLU code. Add the prefix 9 for organic crops.
Storage	At 32°–42° and 95–98% humidity. Cover in closed containers or bags if stored for a few days. Scallions are not overly sensitive to ethylene exposure.

This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture through the Sustainable Agriculture Research and Education (SARE) program. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.