We pulled our red onions from their beds last week. Onions can be harvested and eaten at any stage, but allowing them to grow to full maturity and cure means their flavor will intensify and they will keep for a longer period of time.
When onions reach maturity, their stems will weaken, fall over and dry out - their bulbs fatten. Last year the onions didn't bulb up as they should, so we gave our plants an extra nudge this year by knocking their stems over early to encourage senescence - we wanted them to stop growing and finish rounding out. The onions seem to have been glad for the help; they are fat and healthy. We are happy.
To begin the curing process, we laid the onions out in rows in the field. The sun and heat dries out the onions, but they can also get sunburned and damaged if left out too long - in this arrangement, the leaves of some of the plants shade the bulbs of others and offer a bit of relief from the sun.
After a few days, we collected the onions from the fields and brought them into our hoophouse, where they will continue to cure while being protected from the sun. The necks will dry out, the outer skin will become thin and papery, and with the moisture changing in the bulb, they will lighten and mature in flavor.