I think your Bulb Size problem is you're using onion sets... Use the onion plants if you want large storage onions like you buy at the grocery store... I've been growing a garden for almost 50 years... We only use onion sets for green onions They never get large bulbs only about 1-inch bulbs... We always use onion plants you can buy at your local garden centers in a bunch with about 60 plants per bunch... There is a good site online called Dixondale Farms with all the plants and growing info you would need to know to grow nice large onions... Google it...
I think your Bulb Size problem is you're using onion sets... Use the onion plants if you want large storage onions like you buy at the grocery store... I've been growing a garden for almost 50 years... We only use onion sets for green onions They never get large bulbs only about 1-inch bulbs... We always use onion plants you can buy at your local garden centers in a bunch with about 60 plants per bunch... There is a good site online called Dixondale Farms with all the plants and growing info you would need to know to grow nice large onions... Google it...