Certified Organic Onion Transplants PLANTING GUIDE
When your onions arrive REMOVE THEM FROM THE BOX IMMEDIATELY and keep them in a well-ventilated area, WITHOUT WATER OR SOIL until you are ready to plant.
Your onions are dormant and may appear dry. As a member of the lily family, onions can live off of the bulb for approximately three weeks. We recommend planting within one week.
Sun Requirement: Onions require full sun - the more the better! Avoid growing onions next to crops that might shade your onions.
Soil Fertility: Onions prefer soil with a pH between 6.2 and 6.8. If your soil is too acid, add ground limestone; if it istoo alkaline, add peat moss. Added compost or a balanced organic fertilizer is needed to grow big, mild onions if your soil fertility is low. For the best growth and yield, onions need fertilizer at planting time and additional side dressing.(see "Planting" and "Fertilizing" below).
Planting: Onions grow best on
raised beds or raised rows at least 4" high and 20" wide.
Plant your onions 4 to 6 weeks before the last estimated spring
freeze.
Fertilizer Trench: Dig a trench 4" deep and 4" wide and incorporate ½ cup
fertilizer per 10 linear feet of row. Cover the fertilizer with
2" of soil.
DO NOT plant onions in the fertilizer trench.
Plant the onions 6" from the edge of the trench on both
sides of the trench. Plant the onions 1" deep and no deeper. Onions planted deeper than 1" may not bulb to full size.
If you want the onions to grow to maturity, space them 4" apart. If you prefer to harvest some earlier as green onions, space them 2" apart and pull every other onion during the growing season, leaving the rest to grow to maturity.
When planting several rows of onions, leave 16" between beds. The spacing from the center of one fertilizer trench to the center of the next should be 36".
Watering: For the largest bulbs, onions require 1" of water (rain or irrigation) weekly. Onions have shallow roots and need to be watered immediately after planting, and regularly thereafter. Drip irrigation is preferred to overhead irrigation, which may contribute to foliage diseases. If leaves develop a yellow tinge, cut back on watering. The greatest need for water is closest to harvest time.
When the onion tops start to fall over, stop watering and let the soil dry out before harvesting.
Fertilizing
Every 2 to 3 weeks after planting, sprinkle a balanced organic fertilizer or compost on top of the original fertilizer trench
at the rate of ½ cup per 10 feet of row and water. Stop fertilizing when the onions start to
bulb (see Bulbing below).
Weeding
Onions to not like weed competition! Keep onions well weeded and the soil loose with shallow cultivation.
Avoid allowing soil to cover the onion plants or their expanding bulbs so that a natural bulb will form. If mulching with a light layer
of straw to help control
weeds and preserve
moisture, be sure to push
the straw back when the
plants start to bulb so
they will cure properly (see "Bulbing" below).
Insects
The onion thrip, a light-brown insect that causes deformed plants with slivery blotches, is the most damaging to onions. Thrips overwinter in weeds so it is important to keep the garden or field weed free. Neem Oil can be used to combat the onion thrip.
Bulbing
When the ground starts
to crack as the onions
push the soil away, the
bulbing process has
begun. Stop fertilizing
at this point.
Harvesting & Curing
it's time to harvest when the tops of the
onions turn brown or
yellow and fall over.
Bending the tops over early will decrease bulb size. Proper treatment at harvest maximizes storage time.
Pull the onions early in the morning on a sunny day and dry ("cure") the onions in the sun for two to three days. To prevent sunscald, lay the tops of one row over the bulbs of another. Onions must be cured thoroughly to avoid rot problems. When properly cured, the entire neck (where the leaves meet the bulb) should be dry all the way to the surface of the onion, and the skin will have a uniform texture and color. If the weather does not permit outdoor curing, you can dry your onions indoors by laying them out in a well-ventilated area. Drying indoors may take longer than outdoors.
Once the onions are thoroughly dry, clip the roots and cut back the tops to one inch or braid uncut tops together and hang onions in a well-ventilated area (see "Storing" below).
Storing
Store onions in a cool, dry, well-ventilated location, such
as a garage or cellar. The best way to store onions is at near freezing temperatures with 65-70% humidity and in mesh bags or netting
to permit better airflow. Periodically check for any soft onions and remove any that may have begun to decay.
- Custom Growing Program for Short & Long Day Onions
- 2010 - 2011 Varieties
- Printable Onion Brochure