Question: what is the difference between long and short day onions?
Answer: Long-day onions need about 14 to 15 hours of daylight to bulb. Short-day onions need 10 hours of daylight. Day-neutral onions form bulbs regardless of daylight hours and produce well in almost any region. As soon as daylength hits the 10-hour mark, a short-day onion starts forming a bulb.