We usually grow leeks in the sharing gardens—they are high value compared to onions, which are readily available at a low cost, but harder to grow well (most farmers hill them to get more of the delicious white part) and they take ALL season.
At the hub this year, folks loved scallions. And every year, my favourite onions are the hearty spring onions–the early thinnings farmers harvest and sell to leave room for their sweet onions to bulb up (like the ones pictured above). So I have been thinking about an experiment in the sharing gardens–timelines of sweet onions that we harvest early with the greens on? And also working toward having a continual harvest of scallions for our market table. And winter onions too maybe–hmmm… exciting possibilities to consider as we plan our gardens. Let’s not forget perennial onions that can be an excellent food for pollinators as well as people.
So with onions on the brain, I wanted to get a little nerdy–there is so much to think about with onions and every year I learn something new. So here are a few things I’ve learned along the way.
Seeds vs. Sets.
So you can get sets–the little mini-bulbs that were grown the previous year. They are easy to plant (similar to garlic), get big nicely and if you don’t get your onion seed in early or don’t have an indoor seedling area, they are an option.
But they treat them with a chemical to suppress them from sprouting over winter (since their natural growth process has been interrupted). So onion sets are NOT organic. Further, with our unpredictable weather, onions grown from sets are even more likely to bolt and send up a flower stalk before you harvest.
So if you decide, seeds, yes, that’s the way for me. Then it’s time to get your seedlings started.
Now, you have just to figure out, which variety to grow. First off, we find fresh seed is essential–onion seeds are one of the few that don’t have great longevity.
For scallions we usually plant kincho–they are dependable and upright. If you want a heartier scallion, you can try pacific 22 (white) or apache (red) and they will bulb up to the size of a pickling onion. At the farm, we tend to plant seeds in successions every 3-4 weeks and then transplant them out 5 weeks after seeding, starting the first week of Feb. Under plastic cover, you can harvest green onions through the winter–transplant your last timeline in September.
For larger onions, ideally you will start seeds in the 3rd or 4th week of January but if you get them in now, you will probably be ok but choose a variety with few days to maturity (such as Redwing as oppose. Make sure your seed is for long-day or day-neutral–day-length triggers bulb development.
Sweet onions need to be eaten within a couple months of harvesting and are best if you want to harvest young with the greens–we love walla walla. Storage onions, rosa di milano or calibra, last the whole winter if properly cured (when the greens die back, harvest and leave in the sun for a week, covering at night to protect from dew.)
Overwintering onions need to be started in early July, and transplanted by the middle of August, and will be ready in June the next year. Again, walla walla for overwintering.
Perennial onions (edible plus good for pollinators. potentially even act as a pest deterrant. and either self-seeding or cut and come again–easy.)
Egyptian walking onions–we love them. Easy and quick compared to bulbing onions. Essentially you can harvest the seeds and then plant the little bobules (not the technical term!) like sets; then harvest them like green onions (pulling the whole root out of the ground) when they size up–harvest some but leave some to produce more seed. You can just pop them in where you have room in the garden, between head lettuces or a chunk of bed where you ran out of seed and in 2 months voila, more green onions.
Nodding onion: a beautiful edible landscape onion, flowering in July-August, that we like to interplant in the food forest and flower areas in the gardens. When harvested before it flowers the stalks are tender and according to salt spring seeds: “better than chives.”
Chives–wonderful to throw in any edge or with flowers as well. If harvesting, the trick we use for keeping them fresh: put a small amount of water in the bottom of a plastic bag and stored upright in the refridgerator. These are also amazing food for pollinators, especially in the early season. Love the cut and come again process.
Interplanting: a last experiment to consider
In nature, you often see a collection of different plants growing together in the same area, the plants probably have different light needs and soil needs so they don’t compete but can actually benefit each other. Here is one combination with onions but if you consider the different needs and timing of plants–there are all kinds of combinations that might save space or increase the resiliency in our sharing gardens. So in this combination, we mix onions, carrots, and lettuce in the same garden bed. These three plants have different leaf forms, light requirements, and rooting depths, which makes them compatible both physically and in terms of their resource needs.
Further resources:
http://www.rodalesorganiclife.com/garden/onions-growing-guide