This article originally appeared in the January 2021 issue of Growing for Market Magazine. 

As a result of being in the right place at the right time, the Applegate Valley of Southern Oregon in March of 2018 and 2019, I had the opportunity to work side-by-side with Dr. John Navazio to select the last two generations of his ‘Rossa di Milano’ onion. The selected strain made its debut in the latest Johnny’s Selected Seeds catalog, where it is tagged, “your new favorite onion.”

I can vouch for that. This onion won my heart. Sorting through mountains of stored Rossas, each one was a treasure, perfectly formed with a rosy glow that evoked feelings I never imagined having for an onion. In our days spent communing over the onion bin, Navazio shared with me the secrets of his craft and the journey of the ‘Rossa di Milano’ onion.


The tale of Rossa di Milano

‘Rossa di Milano’ is not a new variety. You have seen it in other seed catalogs or even grown it yourself. The onion is an old Italian, open-pollinated variety that has been in the seed trade for many years. So you are wondering, what’s the big deal with this new release? This particular lineage of ‘Rossa di Milano’ has run the gauntlet of harsh conditions, pests, and disease, to then be hand-selected by Navazio, along with his supporting cast of onion experts, organic farmers, and me through at least ten generations.

Selectors scrutinize each onion entering the population for its shape, color, sheen, neck size, splitting, sprouting, fish-lipping, and ability to, as John puts it, “smile back at you.” (Fish-lipping is when the onion starts to break dormancy and push out on the root end.) Above all, Navazio selects for flavor, tasting a tear-jerking amount of raw onion in the process. In the end, Navazio has delivered a modern strain of an old classic, a superior ‘Rossa di Milano’ that stands up to the top-performing commercial varieties of the day.



A mostly nice-looking box of Rossas, with a little fish-lipping waiting to be sorted out. Fish-lipping is what it’s called when the onion starts to break dormancy and push out on the root end.


When Navazio joined Johnny’s breeding team in 2014, the ‘Rossa di Milano’ project was already well underway. You may know Navazio from some of his other contributions to your annual crop mix, such as ‘Touchstone Gold’ beet, ‘Peppermint’ chard, ‘Cool Customer’ cucumber, and ‘Equinox’ spinach. Or maybe you are familiar with his book, The Organic Seed Grower: A Farmers Guide to Vegetable Seed Production, which has earned him a cult following among a certain crowd of seed enthusiasts. His work has focused on biennial crops, which produce seeds after two years, creating a more complex breeding cycle. Trends have been toward advancing hybrid vegetable varieties, which have become industry standard in many crops. Contrarily, Navazio has remained committed to the noble pursuit of breeding improved open-pollinated varieties.

In the 1970s and 1980s, a few notable seedsmen pioneered the trend of importing unique seed varieties from abroad to sell in their catalogs: Rob Johnston, founder of Johnny’s Selected Seeds; Steve Solomon, founder of Territorial Seeds; and Shep Ogden of Cook’s Garden, which has since been acquired by Burpee. Navazio grew his first ‘Rossa Di Milano’ from Cook’s Garden in the student housing garden while a Ph.D. student in Wisconsin. He immediately saw its potential and passed it along to his friend Steve Peters at Seeds of Change. Having a keen eye for good vegetables, Peters took up the ‘Rossa Di Milano’ and began trialing it in other latitudes.

Years later, Peters sent Navazio on a mission to the Applegate Valley, where ‘Rossa di Milano’ is still grown for seed production today. Peters tasked Navazio with training growers on the art of selection and maintenance of open-pollinated populations. ‘Rossa di Milano’ was one of a handful of cultivars tended in these efforts. In the past two years, I have joined Navazio and his onion growers in the ongoing process, which entails examining each onion out of stacks of bins and choosing the most exemplary specimens for planting the next generation.


Traditional plant breeding

Understanding the difference between hybrid, open-pollinated, and heirloom is useful here, so let’s take a shallow dive and examine these three techniques in traditional plant breeding.  In my former role as a Commercial Sales Rep for Johnny’s Seeds, I worked with thousands of vegetable growers and found some were knowledgeable on this topic, while to others, it was altogether foreign. What I can offer here is the same practical explanation that I would give to customers.



Open-pollinated (OP) varieties reproduce subsequent generations the same as the first, in contrast to hybrid varieties, which are not faithfully reproduced through seed saving. OP cultivars may be self-pollinated or pollinated by others of the same variety. Saving seeds from OP crops, as long as the parent plants were isolated and not cross-pollinated by other varieties of the same species, will reliably produce the same crop in the following year. When purchasing seed, OP varieties are generally lower in cost because the expense to produce the seed is significantly less. There is usually less investment made by companies in the development of these varieties.



John and friends looking for the onions that “smile back at them.”


OP varieties and hybrids alike may be protected as intellectual property, so it is imperative to know their status before reproducing the seed. Plant Variety Protection (PVP) cultivars can still be used to form a cross and create a distinctly new variety, although cultivars under the newer plant utility patents may not be used in plant breeding. The utility patent also prevents seed saving for commercial sale or personal use.

Navazio emphasized, in our conversation about his breeding work, that a variety must be a good seed producer to be kept in the program. “A hallmark of my program is to get involved in seed production to ensure that it is as strong flowering in the second year as it was producing the vegetable in the first year.” Abundant seed productivity is an essential consideration for a variety to be sustainable in the commercial market.



The onions with the best traits have mesh bags full of flies put over their flowers to ensure complete pollination.




The term heirloom is equivalent to a family heirloom or antique. Simply, it is an old variety that has passed down through a lineage. Heirloom should not in any way imply organic. Open-pollinated, heirloom, and hybrids are all grown and sold as either organic or conventional. All heirlooms are open-pollinated, but not all open-pollinated varieties are heirlooms. There is no assurance of good flavor or production quality that comes with the title of heirloom. I point this out because there seems to be a common misconception that heirlooms are inherently more flavorful or somehow more valuable.



Dr. Navazio enjoying some of his work, cooked for once, at a Culinary Breeding Network event.


Liken an heirloom seed collection to a junk shop, where you are sure to find a few hidden gems worth snatching up and some curiosities to marvel at, but they lie buried in the heap. In his pursuit of great flavor and production quality, Navazio sifts through the rubbish, finds the gems, and uses them as the base of his crosses to enhance the desirable traits that have kept these varieties as long-time favorites.

A bred OP does not become an heirloom with age if it lacks the family lineage. Navazio points to ‘Detroit Dark Red’ beet, introduced as a commercial variety in 1892 by Detroit-based Ferry-Morse company. The city had a hopping fresh market scene in those days and the beet was favored among local growers. It remains an industry standard to this day. Because it originated from a seed company, ‘Detroit Dark Red’ is not an heirloom.

On the other hand, Kent Whealy was inspired to create Seed Savers Exchange after he inherited two heirloom varieties from his Bavarian grandfather-in-law, ‘Grandpa Ott’s’ morning glory and ‘German Pink’ tomato. The role of Seed Savers Exchange was pivotal in the rise of heirlooms and shaping Navazio’s interest in the origins of crop varieties and the craft of plant breeding.



Hybrid (F1) seeds are often more costly due to the added expense of production and development. They have a reputation for more efficient production, advanced disease resistance, increased uniformity, and overall vigor. Hybridization is not genetic modification, instead, it is a tool of traditional plant breeding. Cross-pollination of two distinct parent lines creates hybrid seeds. Breeders combine traits of parent lines to produce desired outcomes in the first filial generation (F1) after the cross.

Most development in commercial vegetables is in this sector. For the commodities market, maximum yield, disease resistance, shippability, and uniform specifications are often prioritized over culinary attributes. Nazario sums it up: “Plant breeding is like juggling. There are only so many balls you can keep in the air. If you are juggling too many traits, balls will start dropping.”




The art of selection

Navazio speaks eloquently of plant breeding and is known for his many aphorisms. When asked about the importance of breeding in the final product of a farmer’s produce or a chef’s dish, he offered a quote from his grandmother: “You can’t turn a sow’s ear into a silk purse.” Meaning, the breeding forms the fabric of the food. Of course, enough stress during the growing cycle of a crop, or poor conditions in storage, can make a good vegetable go bad, but in general, a variety bred with a good flavor profile will hold onto it. A vegetable with inferior flavor, on the other hand, will never be made into something grand.

In his breeding, Navazio will discard any material that does not exhibit exceptional flavor, even if it checks the other boxes. He proclaims his top plant breeding aphorism is this: “It ain’t what you keep; it’s what you throw away.”

The breeders and research team at Johnny’s are sticklers for flavor, a legacy of Rob Johnston, founder of the company and an accomplished breeder and seedsman himself. Navazio is no exception. He resolutely claims to have personally tasted “every freaking onion that went into the ‘Rossa di Milano’ line!” And immediately follows with, “that might be an exaggeration, but you get my point.” I know he isn’t far from the truth because I have spent enough time hanging around behind the scenes in the lunchroom at the Johnny’s research farm in Maine, where Navazio has his office. He credits black coffee as the key to refreshing the pallet during a long session of raw onion tasting.


The lowly onion

“The lowly onion,” Navazio laments. Onions are one of the most widely consumed vegetables globally, spanning the range of world cuisines. Yet, they are sold as a commodity in the US, with little regard for flavor. Suppose you are an onion connoisseur who enjoys exploring the nuance of pungency and discussing the finer points of sweetness. In that case, you will find yourself right at home at the lunch table with Navazio. He gave me some guidelines for what he selects for in his flavor trials. Navazio describes the key culinary attributes as characteristic taste, sweetness, absence of harshness and texture.

“First off, it has to taste like an onion,” Navazio explains. Each vegetable has its signature feature and this must be present above all others. For an onion, that is pungency. An onion must meet a certain baseline level of pungency for it to taste like an onion. “When breeding, go for the characteristic flavor,” he advises. Beyond that, there are secondary characteristics that are important to complement the primary.



There’s always more sorting and tasting in search of the best breeding material. All photos courtesy of the author.


Sweetness is a secondary characteristic of onions. Navazio adds: “All good onions have a degree of sweetness to them. If they are not somewhat sweet — they are mediocre at best, if not poor.” Our tastes evolved to seek out sugar, and, as he says, they need enough sweetness to “deliver the goods.” The sad truth is that many modern onions don’t deliver the real goods on flavor and have enough off-flavor to get people sour on them

Off-flavors can spoil the stew. Harshness, in particular, is what Navazio points to as the common offender. “Those of us who care about flavor in vegetable breeding realize that the harshness is what can produce a subpar variety,” he said. “And that, I truly believe, is what turns people off on a vegetable.” Cooking can ameliorate an off-flavor but will still leave you with an inferior product in the kitchen.

‘Rossa di Milano’ is a winner in taste with well-balanced sweetness and pungency that lends itself to cooking or eating raw. The color is not a true red or a yellow, more of a blush. Another standout feature is the extended storage life. Ideal storage conditions are dark and just above freezing. Although Navazio will tell you about his work: “I don’t know that much about storage; I’m doing it as half-assed as most people. I don’t want to do it perfectly. We use CoolBots, and if the onions don’t make it to April – they are out of the program.” This sentiment is typical among plant breeders; they need to know that their material can stand up to the real tests. For ‘Rossa di Milano,’ the real test has been in the field.


Turning up the pressure for resistance

When Navazio began screening onions 10 years ago, he was excited to find that ‘Rossa di Milano’ and some other Italian heirloom varieties showed some natural resistance to thrips. There is always a degree of variation in susceptibility and Navazio has a trained eye to spot this. In this case, the Italian onions were significantly better than the highly susceptible varieties. He knew he was onto something. “By year two in the onion breeding nursery, I realized the best thing I could do is bear down with randomized control trials in the field, minimize rotation to ensure heavy pressure from thrips and Botrytis to start building the resistance to insects and disease,” he recalled.

Since Navazio began his onion program a decade ago, thrips seem only to have become more of a problem for farmers. “Thirty years ago, not many people were talking about thrips,” he said. Not only are thrips a problem for the damage they cause by scarring the plant, but their bite also creates a wound that is open to infection by any number of viral, bacterial, and fungal diseases. Iris Yellow Spot is an example of a thrips-transmitted pathogen that has recently swept in and devastated onion crops.

There is no single gene that confers immunity to thrips. But this is where Navazio’s work with open-pollinated breeding gets interesting. He is a strong believer in horizontal resistance. “When you grow out a large enough pool of genetic variation, you see quantitative degrees of insect damage,” he explains. “It means that there are multiple genetic factors at work conferring degrees of partial resistance. When you see this variation in degrees of resistance variety-to-variety, as well as plant-to-plant within a variety, it lets the breeder know that you can select within a promising variety.”

By selecting the subset of that variety with the best variation and eliminating the more susceptible, he slowly builds stronger resistance in that population. It is “one of the great beauties of using the methodology of population breeding where you’re not making narrowly selected inbred lines,” he says.


the-tale-rossa-di-milano-onion-peeling-back-the-layersThe author with Dr. Navazio.


The latest ‘Rossa di Milano’ project began over a decade ago by searching the world for older heirlooms and suitable OP varieties that do not have any proprietary ownership, then screening up to 140 different populations and subpopulations, selecting from the best of those, and making crosses. As a breeder, Navazio works meticulously on all his varieties to deliver tried and true pest resistance, field toughness, lasting storage, aesthetic appeal, and exceptional flavor.

Thrips resistance was the first trait to lead the selection, followed by earliness in the long-day category. This particular strain of ‘Rossa di Milano’ is up to 10 days earlier than others of the same name. Then, of course, it has to taste great and store even in non-ideal conditions. It must have a tight wrapper, a delicate neck that will dry quickly, a rose-gold sheen, and the classic flat-top tapered shape.

The Navazio strain of ‘Rossa di Milano’ is sure to garner oohs and aahs from customers through the winter. Be assured the breeder himself had that goal in mind in every step of the process. “We believe in farmers making money in lean months when cash flow is low,” he says.

In addition to the Rossa, Navazio has other onion classes in his program that hold the same high standard: yellow storage, red storage, cippolini, and super early semi-storage. He specializes in biennial crops beyond onions; other projects include beets, carrots, Swiss chard, spinach, and sprouting broccoli.


Megan is GFM’s California-based traveling Field Correspondent and Business Development Consultant. She works as an Organic Inspector for CCOF and formerly as a Commercial Sales Rep for Johnny’s Selected Seeds. Follow her on her journey at @megan.alluvial.