Plant Profile- Spring Onion (Allium fistulosum)

Spring onions are a crop that has finally reached its potential after many years of experimentation and development. It serves as a good example of how I go about growing vegetables, so rather than just list boring details about when to sow and how to eat it that you can find anywhere I will instead mostly focus on how my relationship with this species has changed over the years.

Alliums are on the whole a more temperate genus than our climate accommodates. I have grown red salad onions once before after extensive searching to find a variety that will form bulbs at our latitude since each strain uses changes in day length to trigger maturation. They needed to be germinated in a pot, transplanted out into a very highly enriched bed and watered constantly to size them up enough to form good bulbs that matured all at the same time. The resulting onions tasted significantly nicer than store bought red onions but had terrible storage properties, so most of them tasted about the same by the time I got around to eating them. All that work for something that only costs a few dollars in the shops. On top of that it is difficult to produce good quality seed from a limited gene pool if they would flower at all for me. Garlic is similarly challenging, previously growing but not producing useful bulbs. That has changed recently but I will save the details for a future post. One member of the alliums that has proven useful is garlic chive (Allium tuberosum). This species is more perennial and goes dormant during our cold and dry winter and spring, producing a decent crop in late summer through autumn if we have good rains.

Our main allium is the spring onion. I have grown them here for about ten years on and off, initially in more intensive irrigated beds and now with zero input methods. To start I bought seed of one or two varieties at a time. The seed has a fairly short shelf life and commercial seed quality is very variable, so I usually germinated them in a pot in late summer and transplanted them out in clumps of about three in early autumn. The initial crops I grew usually failed to flower or produce seed when left in the bed, though one strain finally managed to produce a few weak flowers and a little seed. This variety appealed to me a lot as it formed very large and robust plants with a deep blue hue due to a thick waxy layer on their leaves that allowed them to stand up to dry conditions.

The following year I decided that the crop had shown just enough potential to take it seriously. I widened my scope and purchased about twelve different named varieties and once again grew them from seed. About two thirds of this seed germinated, with everything from a thick lawn of vigorous ones to zero sprouts under identical conditions. Until you see this kind of side by side comparison it is easy to be sceptical about the wide variability in commercial seed quality. They were transplanted into a new vegetable garden quite far from the house that was abandoned to the weeds after about six months in early spring. About half of the varieties survived this treatment but I lost track of labels and names along the way. Where I was going they wouldn’t matter anyway. I waded into the weeds and transplanted out the surviving spring onions to a bed closer to the main house in late spring. Once they settled in about a third of the plants flowered over a fairly long time period over summer but the majority never flowered. Visual comparison revealed at least a handful of different original varieties were flowering together and most likely crossing based on the frantic bee activity. I didn’t care about which variety was which since anything that could germinate, grow and flower was allowed to contribute to the gene pool. Seed was collected and pooled over this time as well.

When the autumn of 2019 rolled around, about a decade since my first dabblings with the species, I had my first large quantity of home grown seed. I had never direct sowed the seed before since it was too scarce, expensive and unreliable from commercial sources, but having my own stocks changed everything. I prepared a 15 m long bed with two rows, hoed shallow seed beds, broke the underlying compacted clay to about 5 cm with a shovel, then sowed as thickly as I could. Instead of burying the small seed in the unimproved clay I collected pulverised animal manure and leaf litter from a nearby concrete slab where my geese and goats congregate and used that to cover the seed. This brought in a bit of weed seed but resulted in acceptable germination during our wet early autumn. Given I was uncertain how effective direct sowing would be I also made up a few large pots of seed. These proved useful for filling in gaps in the bed by transplanting them later. This hybrid planting strategy reduced the risk while also reducing the work load of transplanting that entire huge bed by hand.

The bed closest to a hedge was selected for the spring onions since they are relatively shade tolerant. The row closest to the hedge was significantly smaller by the end of winter but caught up once the sun moved higher in the sky. The small seedlings were hand weeded once with a hoe then butter knife up close then ignored for the rest of autumn and winter. This allowed a fair bit of weeds and grass to grow around them but the shallots still put on a decent amount of growth. In late winter the beds were hand weeded again and a surface layer of fresh goat manure applied between the two rows, along with a generous sprinkling of wood ash. The plants jumped in size again after this.

Currently the first of the shallots are starting to flower. When the plants go to flower they exhaust much of their resources and often die. This means the useful harvestable span of the crop is reduced as the unflowered plants will remain in useful condition well into mid summer. My current plan is to start harvesting the earliest flowering shallots to try to eliminate this trait from the population. Ideally they should start flowering together in early summer. This also gives the garlic chives a chance to get going so the two allium species can complement each other and provide a similar vegetable product all year around.

Apart from the initial applications of goat manure and ash, the germination layer of leaf mould, and a second manure and ash application the crop received no additional fertiliser. Apart from the ample rains during our wet autumn during establishment where the paths were usually 5 cm deep puddles the crop received no artificial irrigation. The beds were hoed up in preparation over summer and weeded twice so far (a more intensive task the first year on virgin ground provided weed seeding is limited from here on). The crop received no spraying or pest protection of any kind. The soil was only dug roughly to 5 cm deep directly under where the seed were sown and was otherwise left as untouched compacted clay that is like glue when wet and concrete when dry (though close inspection shows it is riddled with worm burrows of varying sizes).

Throughout autumn when the crop was establishing I was still harvesting the tops off last year’s crop that had managed to persist. When cut cleanly off the roots the plants will usually regrow. Individual leaves can also be harvested and the growth of the plant will be less interrupted. The large crop started to be harvested after about three months. Now that our dry spring is here (already 35 C in early September) the crop will power on and continue providing tasty greens for stirfries and soups for another three months at least until flowering begins (and the ones reluctant to flower will keep picking until late summer most likely). At this scale I now have enough to share seed more widely while also providing all our household needs. Increasing the growing scale would just result in more crop than we can eat.

Hopefully all this outlines how growing with limited inputs is possible but requires a big shift in approach. Instead of treating species of vegetables like a piece of furniture picked out of a catalog you need to treat them like a friend, and friendships require attention, consideration and adaptation so that both parties can benefit.

Main bed of spring onion with goat manure/ash top dressing between rows
Last years spring onions still going strong among the weeds

4 thoughts on “Plant Profile- Spring Onion (Allium fistulosum)

    1. Named varieties are usually narrowly selected in order to give consistent qualities and performance (really important under intensive production). I want to maintain diversity and inconsistency in my population so I don’t think I can give it a name in good faith. I will probably mix in a bit of new seed every five years or so if I feel like it. This is more like how crops used to be grown with neighbors occasionally swapping seed and bees moving pollen between gardens. Collectively each region shaped the locally grown varieties this way. I do like the trait of being large and blue, so maybe “Blue Meanie” would be a fun name for the line as it improves.


      1. You could slap a ‘grex’ on the end and call it good. Seems to be the fashion with people doing similar breeding trials here in the US anyways.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: