How a research facility in Leamington developed a top secret tomato that could take on the world

The Tomato Breeders Round Table is one of the most anticipated events in the industry. The top breeders, from all the big seed companies, are there and strangers will approach them, recognizing them because of the tomatoes they’ve created, just looking to talk.

“There’s a lot of fame involved as a breeder,” said Patrick Sheridan, who oversees Heinz seed research as a global vice-president for parent company Kraft Heinz. “You can think of them more as performers, artists, rock stars.”

Last year was the first time Heinz sent MacLellan to the roundtable. It was at a hotel in Monterey, Calif. Walking around, MacLellan recognized Steven Schroeder, a breeder with Nunhems.

“He made N6438,” MacLellan said, “which is a thorn in my side.”

At the roundtable, no one came up to MacLellan, no eager grad students wanted to gush about her tomatoes. And that was fine, because the idea of strangers sidling up to her at cocktail mixers, conference ID badges swinging from lanyards around their necks, makes her wince. 

“I hate any kind of attention ever,” she said.

The drive, for her, is more personal. It’s the sort of thing most non-breeders can’t really understand. An outsider will walk through a tomato field and see rows of the same green vines. MacLellan walks through the rows and sees one variety with an average fruit size of 70 grams — about five grams better than its neighbour.

The way she put it, walking through a field is like walking past a crowd of kids. They can almost look faceless, just generic kids, she said, “unless one of them is yours.” 

MacLellan creates about 300 experimental tomato varieties a year. For some of those plants, she also created the parents, and potentially even the grandparents.

“People think I’m crazy. My friends and family, they’re like, ‘They’re just tomatoes,’ ” she said. “Every single one of them is like a child of mine.”

From the road, the Heinz farm in Leamington looks like a small family operation, not a research facility run by one of the biggest food conglomerates in the world. The faded sign out front has somebody’s last name on it. And at one point this summer, a piece of used farm equipment was sitting out on the front lawn, marked for sale. Even if you drive down the dirt laneway through the property, you won’t see the experimental tomato patch. Heinz arranged for cornstalks to be planted around the perimeter like a privacy fence.

“There are rival companies, maybe breeders without morals, that can be nefarious,” MacLellan said. “And you know, they would do anything to try and get their hands on high-value germplasm.”

For almost 30 years, Heinz has been developing germplasm, or genetic material, in Leamington, about 50 kilometres from the Windsor-Detroit border. It was making ketchup in the town for even longer, until about 10 years ago, when the company announced it was pulling out of its historic tomato processing factory in downtown Leamington and shifting production to the United States. The move sparked a fierce backlash, with consumers boycotting Heinz ketchup in Canada. 

In 2021, however, Heinz publicly atoned, moving ketchup production back to Canada, at its factory in Montreal. But the company says the tomatoes are coming from Leamington. Highbury Canco, which took over the Leamington factory in 2014, sells Heinz the paste for its Montreal-made ketchup as part of a four-year, $1-billion deal.

To make good paste for ketchup, your tomatoes need a lot of meat, according to Highbury Canco CEO Sam Diab, who was the manager at the factory when it was run by Heinz. To understand tomato meat, picture a tomato cut crosswise. It looks kind of like a wheel. The tire wrapping around the outside is the tomato’s meat, what people in the industry call the wall. The centre, where the spokes are, is made up of the seeds and the gel.

Processors want tomatoes with big, thick tires — truck tires, not bike tires — because more meat means less water, making it more cost effective to cook them down into a paste.

The tomatoes also need to be firm, so they aren’t bruised or crushed if they end up at the bottom of an 80,000-pound load in a truck. And they need to be all roughly the same size, deep red, with high ratings for sweetness and viscosity. In the field, the plants have to be able to withstand pathogens, dry spells, heavy rains and early frost. Whatever happens, really, they must produce tomatoes. Farmers all over the world, and the major international enterprises they supply, depend on it.

Harvest time is when MacLellan starts to feel that pressure the most. She spends nearly every daylight hour in her secret tomato patch, with her tablet and a serrated pocket knife, testing tomatoes and making decisions about what to advance to the next stage and what to give up on. At night, she continues to work in her dreams.

There is one dream she has over and over, in which she is opening a packet of seeds to start a new trial. The packets are rectangular manila envelopes that Heinz guards like money, locked in a vault.

In the dream, MacLellan is at her office, or in her house, her backyard, the arena in Leamington, at Disney World with her kids. Wherever she is, in that moment, it makes total sense that she needs seeds immediately. But there’s nothing in the packet.

“And then I’ll toss and turn in bed until my husband is like, ‘What’s wrong with you?’ And I’m like, ‘Ah, tomatoes.’ ” 

MacLellan was at her kitchen counter, toward the end of August, when the nightmare started to come true.

Her kids were playing outside and she was going over field maps, getting ready for her trip to Europe in a few days. She was visiting farmers in Italy, Portugal and Spain, who were growing some of her experimental varieties, to give Heinz a better idea of how the new plants performed in different regions with different farmers.

Last year, H2590 had excelled in Europe. And with tests in Leamington and California looking good, another strong European season would almost certainly mean it would advance to the next phase — a tryout position in the Heinz seed catalogue. The catalogue offers more than 60 varieties to growers and major food processors — not just for use in Kraft Heinz products. Heinz estimates that its tomato varieties end up in two out of every five tomato products, of any brand.

If customers liked it, H2590 would be well on its way to becoming a top tomato. 

But as she scanned the maps, which marked where each variety was planted at each European farm, she started to get nervous.

“Where is it?” she thought. 

She looked and looked and H2590 wasn’t there, on any of the farms. She texted the European sales manager for Heinz seed, who told her some of the seed packets, including H2590, had been held up for inspection at the border.

By the time they got to the farms, it was “just a little bit too late for the sowing window,” she said, a few days later, over the phone from a hotel room in Portugal.

She let out a long, slow breath. “Even when I say it out loud, I’m just so disappointed.”

Without data from European trials, H2590 was a long shot to crack the catalogue.

“It really hurts, honestly,” she said, because by waiting another year of trials, H2590 could be missing its chance.

The global seed business is like an “arm’s race,” MacLellan said. Everybody needs new material all the time. So the trick to becoming the top tomato isn’t to be the best ever, it’s about being the best that’s available at the right time.

“Anytime we experience delays on anything, there’s that fear in your mind of, ‘What if?’ ” she said. “What if it had been there? Could it have been the one that made the meteoric rise?”

Among its many virtues, H2590 has a flat nipple. In breeder-speak, a nipple is a sharp tip at the southern pole of a tomato. If the nipple is pointy, or inverted, the peeling machines will trip over them, leaving little patches of skin on canned tomatoes like flecks of toilet paper on a shaving cut.

“I hate that,” MacLellan said, a few days before Heinz would make a final decision on whether to advance H2590 into commercial production.

It was early September and she was pacing around the field in Leamington. The town bills itself as the tomato capital of Canada. In late summer, on the side of almost any road, you spot squished tomatoes that fell from harvest wagons.

People in the area are so crazy about tomatoes that MacLellan has to plant buffer rows of common tomato varieties. She has given up on chasing away the enthusiasts who pop by tomato fields with their baskets, looking to pick a few. But taking them from the experimental varieties would throw off the yield data. So if pickers ask very nicely, she lets them take regular tomatoes from the plants on the outside. 

She also gives a few bushels of tomatoes to her Italian grandmother, who uses them for sauce. “My grandmother still is like, can I have San Marzano? And I’m like, you don’t want San Marzano! I have better varieties! You can have mine.”

MacLellan’s team was harvesting a H2590 plant, shaking the vines and dropping the tomatoes onto a tarp. They separated the red ones from the green into different buckets and weighed each one using a luggage scale. 

MacLellan squeezed one of the tomatoes in her hand. “You’ve got to touch them,” she said. “They’re just, they’re beautiful.”

It was deep red, like it was almost too ripe, and yet it felt hard, like a green tomato.

She took the knife from her apron and cut the tomato across its equator. The walls were thick with meat, as if they had expanded so much they were squeezing out the water. There was no splash, no explosion of juice in the mouth, just stiff, moist, sweet flesh. 

“We don’t breed for taste,” she said.

But scrolling through her notes on the tablet, H2590 was looking strong — Ketchup Pack strong, even. Trials were positive in South America too. Good sugar, good resilience, good viscosity, good colour.

It wasn’t just up to MacLellan, though. Before they could make a final call, a higher-up from California was coming for an inspection.

A few days later, Lynn Veenstra, the Heinz director of North American seed sales, arrived early at the Leamington farm. MacLellan wasn’t there, so Veenstra started wandering around, letting herself be drawn in by plants that caught her eye. She couldn’t tell which was which, though, because the markers in the field have decoy codes on them. 

“Oh that’s intriguing,” she said to herself, noticing a plant full of ripe fruit. It seemed endless, like you could keep pulling up vines and finding more and more tomatoes. 

The plant was H2590. Veenstra looked more closely at it and combed through the data. She wanted to know its weaknesses. 

“Every variety has a weakness,” she said. But so far, with H2590, “I haven’t found one yet.” 

When MacLellan arrived at the field, she recalled Veenstra telling her, “You’re not crazy.”

The two decided the tomato was too promising to wait for more tests. It had to go out now.

So MacLellan placed the order. She sent an email to a Heinz production manager, asking for about 30 kilograms of H2590 seed. That means, as of this week, hundreds of H2590’s mothers and fathers are growing in greenhouses on the other side of the world. Soon they will coax pollen from the fathers and fertilize the mothers. The mothers will grow tomatoes. The tomatoes will be crushed, fermented and strained to extract the seeds. 

By 2026, that 30 kilograms of seed will be shipped to farmers, who will collectively plant as many as 350 hectares of H2590 — just a taste, to see if big processing plants around the world like it and order more. And if they really like it, it could edge out an older tomato variety to become a member of the Ketchup Pack. Growers would plant thousands of hectares of H2590.

After MacLellan sent the email, something clicked. It was like she’d tripped a circuit. All her dreams and fears for the tomato, which had been coursing through her brain all season on a loop, suddenly stopped. 

“OK,” she told herself. “It’s done.”