Allium cepa Days to maturity are calculated from date of direct seeding.
• Onions are photoperiodic plants — they regulate their stages of growth by day length
• Onions will make top growth until the critical light duration is reached, then bulbing begins
• The amount of growth and development prior to bulbing will determine the bulb size
• Long-day varieties do well in northern states where summertime day length is between 14-16 hours
• Short-day varieties do well in southern states and bulb when day length is 10-12 hours; they won't get very large in northern states
• Dividing line between short-day and long-day varieties is generally accepted as 36° latitude, roughly along the Kansas/Oklahoma border
• Day-neutral and intermediate-day varieties start bulbing when day length is 12-14 hours; can be successfully grown anywhere
• Onions prefer light, sandy, loamy soils
• Apply 1/4-1/2 cup of TSC's Complete fertilizer per 5 row feet, 1-2 inches below transplant or seed
• Thin to the strongest plant when 4-5 inches
• Sow up to 10-12 seeds in a 4-6 inch pot
• If tops reach over 5 inches before transplant, cut to 3 inches
• When planting out carefully separate the seedlings and place in a shallow trench
• Fill trench around seedlings and water in well
Insects & Diseases
• Common insects: Onion thrips and maggots
• Insect control: Pyrethrin or Predatory Nematodes
• Common diseases: Fusarium basal rot, pink root
• Disease prevention: 5-7 year crop rotation
Harvest & Storage
• For scallions: harvest when pencil size or larger, wash and trim roots, store in a bag at 36°F and 95% relative humidity
• As bulbs approach maturity, withhold water so protective paper can form
• After about half the tops have fallen, push over the remainder; wait about 1 week then harvest
• Cure in a warm (75-80°F), shaded, well-ventilated location until outer skin and necks are dry, then trim tops, leaving one inch above the bulb
• Store in a cool, dry, well-ventilated area
• Check occasionally and immediately remove any sprouting or rotting onions
What is pelleted seed?
Seed that has been coated with a clay-based material to form a larger, round shape. This makes planting by hand or mechanical seeder easier and allows for more controlled sowing of small seeds such as carrots or lettuce. All pelleted seed has a National Organic Program (NOP) approved coating.
For best results, store pelleted seed in an air-tight container and use within one season.