|i heard that i need to break the tops of my onions so they will get larger in the soil. if so, when do i do it?|
|Onions go through a process called bulbing to produce the onion bulb. Bulbing is affected by amount of daylight. Daylight necessary to initiate bulbing depends on the variety of onion and can range from 12 hours for early maturing types to 15 hours for late maturing types. Mature onion bulb size is highly correlated to the size of the onion plant at the time bulb formation begins. Thus, bulb size is influenced by the same factors which influenced plant growth prior to the beginning of bulbing, plus environmental conditions during the completion of bulbing and maturity. Factors affecting large bulb formation include early planting, space per plant, soil moisture, weed competition early in the growing season, and damage from blowing soil particles, insects and pests.
If you break off the tops, the plant will stop growing. So, allow the foliage to die down naturally at the end of the season. Good luck with your next crop!