How to grow bunching onions with the Paperpot Transplanter

Paperpot settings for bunching onions

Use 6″ paper chain pots, drop 5-7 seeds per cell with the Kwik Klik Slide, and transplant 4 rows on a 30″ bed, 7.5″ apart. Plan on about 3 trays per 100′ bed.

Paper chain pot	6″
In-row spacing	6″
Rows per 30″ bed	4 (7.5″ apart)
Trays per 100′ bed	3
Kwik Klik top plate	Paperpot 264, 3 mm thick, 5 mm holes
Seeds per cell	5-7
Seed per 100′ bed	4,560 seeds (+/-)
Cultivars	Guardsman, Parade, Deep Purple
Germination	72 hours at 78°F
Days to transplant	28 days
Days to maturity	70 days
Harvest window	14 days
Harvest unit	Bunch of 10-12 onions (3-4″ white base)
Yield per 100′ bed	380 bunches

Bed figures are for a 100′ x 30″ bed. From the Paperpot Co. Growers Notes, developed with farmers Erich Schultz (Steadfast Farm) and Seth Davis. Adjust for your climate and conditions.

Bed preparation

• Broadfork the bed to aerate and loosen the soil.
• Smooth and shape the bed with a bed prep rake, removing any debris.
• If the previous crop was fertilized, bunching onions will do fine without reapplying. If not, either layer on 1″ of compost (enough to mostly cover the native soil) or sprinkle on alfalfa meal and pelleted chicken manure.
• If you layer compost, don’t tilth it in, so surface weed seed stays smothered. If you add amendments, tilth the top 1-2″ to mix them in.
• Irrigate for 10 to 14 days* to germinate weed seed in the top layer of soil, then flame weed once the weed cotyledons are up.

Seeding

• Set a germination tray with 6″ paper chain pots and fill with potting mix.
• Set up the Kwik Klik Slide with the Paperpot bottom plate and the Paperpot 264, 3 mm thick, 5 mm holes top plate.
• Pour seed on the top plate and work it until 5-7 seeds sits in each hole. Line the seeder up over the tray and slide the plate to drop seed into every cell at once.
• Water the tray, then germinate for 72 hours at 78°F.
• Move trays to greenhouse benches as soon as you see germination.
• Keep the tops trimmed to 4″ in the greenhouse so the plants put energy into roots.

Transplanting

• Water the trays thoroughly before heading to the field.
• Plant four rows of bunching onions with the Paperpot Transplanter: 7.5″ between rows, 3.75″ from the outer rows to the bed edge.
• New to the transplanter? See the how-to guide and videos.

Bed layout

Irrigation

• Water the bed in thoroughly with overhead irrigation or four lines of drip.
• Without good airflow, overhead watering risks downy mildew.
• Dry conditions give bunching onions an unpleasant flavor.

Cultivation

• 10-14 days after transplanting, cultivate with a wheel hoe and bio-disc cultivator, which works on and between the rows in one pass. It also hills the rows.
• A long-handled collinear hoe works too, just slower.

Harvest

• Harvest when the white base is 3-4″ long, and within 14 days of maturity for the best tenderness.
• Harvest kneeling and rubber-band two cells together for bunches of 10-12 onions.

Washing and packing

• Dunk the bunches in cold water, then spray the roots with a washdown gun. Keep the gun off the green tops.
• Pack in totes and store at 35°F until market.

Bunching onions in paper chain pots: FAQ

Other crops

basil · beets · cabbage · cilantro · dill · fennel · garlic · head lettuce · kohlrabi · leeks · Little Gem lettuce · mesclun mix lettuce · onions · snap peas · salad turnips · spinach · storage radishes · summer crisp lettuce. All crops in one table: the Paperpot growers notes.