Harvesting and Drying Onions

We planted red and white onions on February 1, 2014. Once the green above ground onion leaves were about 4 inches, in March, mulch was added to the raised bed.

Onions signal that they are ready for harvest when the green portion bends at the “neck” and falls over (see “Onion Plant Bending at Neck”). Some people harvest when about 1/4 of the total onion crop has bent to the ground, but we harvest each onion as it indicates it is ready.

Onion Plant Bending at Neck

Once the green portion bends at the neck, the onion bulb will stop growing. Leaving the onion in the ground at this point can result in rot—especially if humidity and temperature are high (as we often experience in this area and further south).

Onions Drying

Post harvest bulb rot is the greatest threat to successful storage of onions. The key to success is to dry onions in relatively cool (75 to 85 degrees F) and dry (low humidity) conditions. If our weather is cooperative, we can dry them on a table in the garage. I have also dried them on a table in the house (see “Onions Drying”).

Place the onions flat (I put them on newspaper) and spaced apart (I stagger the bulbs left and right) to allow the best air flow for drying. The drying process takes about 10 days. The picture below illustrates onion drying from freshly picked (left) to fully dry (right). Once dry, we cut the top off and store.

Stages of Dry Onions

Once the onion tops are dry, the onion can be stored. remove the dried top just above the “neck” of the onion (about an inch above the top of the bulb itself) and remove the roots (see below).

Remove Onion Top and Roots

To ensure that the onion top is fully dry, I leave the onions out on the counter or table for a few more days. The worst thing that can happen to the onion at this time is neck rot — a post-harvest rotting of the bulb (rotting onion produces quite a stench, not easily forgotten once experienced). It has taken 3 1/2 months to get to this stage … just a few more days for successful storage.

Once fully dried, store the same as onions purchased from the store. Enjoy the fresh onions!