With our customers in the south nearing harvest, we wanted to provide a refresher on when it’s time to harvest.

One way you will know your onions are nearing harvest is by keeping track of the number of leaves on your onion plants. While 13 is the ideal number of onion leaves, some onion varieties may mature with fewer leaves than that. When your plants reach at least seven leaves, start watching them carefully. There will be three key physical signs that your onions are mature and should be harvested.

highlander onion

1. Soft Neck

When the area right above the neck (the place where the leaves meet the bulb) starts feeling soft, the transfer of carbohydrates from the leaves to the rings has finished meaning the final cell division within the rings has occurred. At this stage, you should water less frequently to prevent sour skin and black mold occurring in wet soils. 

2. Tops Falling Over

When some of the tops fall over, this reflects 100% soft neck, even though not all the tops are down. If you are planning to consume the onions right away, you can pull and enjoy them. There is good skin development at this stage and adequate green tops to prevent sunscald during drying.

When all the tops are down, the onion is finished pulling sugars out of the top and moisture out of its roots, but skin development will continue to occur. If growing for storage, a light last watering should take place to allow onions to respire some moisture before harvest. For sweeter onions, give them a moderate final watering.

3. Last Leaf

Examine all the leaves, particularly the most recent one to appear (last leaf). The leaf sheaths mature and dry from the oldest to the youngest leaf. If you pull the onions from the soil before the last leaf is dry, rot could occur during storage. The neck cavity or top of the onion should not be sunken or soft before lifting the onions out of the soil.

It’s best to remove your onions in the morning before the worst of the heat and direct sunlight occur.

After Lifting Your Onions

Now that your plants are out of the soil, you’ll want them to last as long as possible. This requires thorough drying and curing. Happy harvesting!