Onions are the second-most consumed vegetable worldwide after tomatoes, and form the foundation of many important culinary dishes around the world. They are eaten raw and cooked, immature and fully mature. Planted and harvested all over the world, they have been adapted by humanity to grow in a range of climatic conditions and regions. As you know, they are also a frequent part of your CSA boxes.
Just because onions are ubiquitous doesn’t mean they are easy to grow. When they are small, onions have just a handful of thin leaves that don’t compete well with weeds. And while they can tolerate a wide range of temperatures, they are sensitive to both freezing and extreme heat at any point in their growth. Because they are descended from plants that grew in swamps, they have shallow roots that require the soil to be kept moist at all times. They enjoy rain for most their life, but once they begin to form skins, it can ruin the crop.
While onions can be eaten at almost any stage of growth, from pencil-thin “scallions” to full-sized bulbs that have not formed skins yet, “dry” onions are by far the most widely consumed. Once they reach this stage, forming a tight skin that protects the flesh inside, they become a crop that can be stored for months if they are kept dry. But you can’t just plant onions at any time and have them grow and produce bulbs.
Biennial plants like onions flower after they have been growing for a year — or if they think they have. The problem is that they become inedible once this starts to happen. In every part of the world, the right “type” of onion must be planted at the right time of year: short day, intermediate day, long day, or day neutral. If the wrong type is planted, it may go to seed before it makes a bulb. Alternately, it might not form a bulb at all.
Terra Firma grows onions almost year-round. We recently finished planting our “short day” overwintered onions that will get harvested in May. Another round — “intermediate day” — will go into the ground in February and mature in late June. And the final round — “long day” — will be planted in April and harvested in August.
All the onions are harvested the same way: their roots are cut and the plants are laid out in “windrows” under burlap sacks to cure and dry in the hot Sacramento Valley sun. Our onion harvest season provides nearly ideal conditions to do this, as rain is rare after May 1st and humidity is generally quite low. Once the skins are fully dry, we transfer the onions into bins and store them in a warehouse with plenty of air movement but no climate control. Most of the time, this provides nearly perfect storage conditions from June until the end of October. We always plan on having all the onions distributed by Thanksgiving, as that is traditionally when our weather shifts from being most dry to mostly wet.
This year has thrown a wrench into the gears of our Fall onion production. Our Summer weather was unusually humid, with muggy afternoons and dewy mornings. The onions we harvested in August took much longer to dry down in the windrows, and the soil under the plants barely dried out at all. We had some bulbs that began to break down, and had to leave quite a few onions in the field. Once we got the onions into the warehouse, we had a nice period of hot and dry weather in September, but when the weather changed in October, we started to see more mold and mildew developing.
I should add at this point that conventionally grown onions are treated with fungicides and other chemicals right before and sometimes after harvest to prevent breakdown in storage — organic onions are not. As the weather has gotten progressively wetter, we’ve had to throw away more moldy onions. At the same time, we’ve been sorting out the bulbs that still look nice, cleaning them up and sending them along to you hoping that they would store better inside your kitchen than they would in our increasingly humid warehouse. However, you may receive onions with internal breakdown that is not visible from the outside.
We are planning on doing one final distribution of onions, in next week’s boxes. When you receive those, you should remove the skins and inspect the onion underneath to see if it is still intact. Black mold can be easily washed off but if the onion is soft or rotting, it’s best to toss it. Place the good onions in a ziplock bag or sealed container and refrigerate. You should do the same with any onions you still have from previous deliveries. Onions will keep this way for several weeks.