I was so thrilled with Sara’s comment on how to grow “comically huge” onions that I have spent some time reading up on onion culture.
Sara wrote: Onions: plant very shallowly, feed, feed, feed and water to put on as much leaf mass as possible before your daylength reaches the # of hours that your variety requires to bulb. Used organic fertilizer and compost last year and grew HUGE onions. Comically huge.
Here’s a really great link I found: Growing Onions, TexasA&M
The size of the onion bulb is dependent upon the number and size of the green leaves or tops at the time of bulb maturity. For each leaf there will be a ring of onion; the larger the leaf, the larger the ring will be.
My onion varieties are all “long-day” onion varieties. They will quit forming tops and begin to form bulbs when the day length reaches 14 to 16 hours. In the Boston area, that happens (15 hours) on May 29. (I used this daylight calculator.)
Sooo…. My plan is: plant shallow, then baby my onions until the end of May. Lots of food and water and sun.
Onion varieties I’m growing this year: Pontiac, White wing, Red wing, and Ailsa Craig.