In 1926, starting with just 10 acres in 1926 in California citrus country near Los Angeles, Harry E. Rosedale, Sr., a young immigrant from Denmark, set out to transform American horticulture.

Today, Monrovia Nursery Company — now based in Dayton, Oregon — is the nation’s largest grower of premium plants by sales and container acreage. They produce over 22 million plants across more than 4,000 varieties annually.

Monrovia has thrived through wars, recessions, and the latest pandemic by maintaining three core principles: a commitment to excellence, innovative plant selection, and nimble marketing strategies.

From flood to flagship

Rosedale honed his propagating skills at Armstrong Nursery before buying 10 acres with a partner in Monrovia in 1926. He continued solo after the partnership dissolved three years later.

Then came the Los Angeles Basin Flood of 1938, “washing all the plants down to Long Beach,” said Katie Tamony, Monrovia’s chief marketing officer.

“He was pretty much wiped out,” she said. But with friends and suppliers rallying, he moved, bought another nursery of the same size, and began again. “This guy had a lot of perseverance.” Rosedale’s enterprise grew steadily through the decades, each expansion reflecting the nursery’s adaptability and vision. By 1952, the business had grown to 80 acres in Azusa, California, where new propagation techniques were refined. Monrovia later added a 750-acre Dayton, Oregon location in 1984, and a 600-acre Cairo, Georgia site in the 1990s. By 2005, it was cultivating 750 acres in Visalia, California. Then, in 2025, Monrovia officially designated its Dayton, Oregon campus as company headquarters.

The Dayton headquarters resembles a Craftsman lodge surrounded by lush display gardens and an outdoor kitchen — the perfect setting for next summer’s centennial celebration August 27, 2026.

“Oregon has become the flagship nursery where we tend to hold the largest customer events, grow the largest variety of plants and do the most shipping across the country,” said Tamony.

Dayton works perfectly for conifers, maples and cold-hardy plants; Visalia grows plants spanning hardiness zones; and site in Cairo focuses on tropicals, hollies, and evergreen magnolias.

Monrovia remains family owned. Harry Rosedale’s son Miles served as CEO until 2020 and continues as co-chairman of the board. The current CEO is Jonathan Pedersen.

Pioneering the modern nursery

Often called a visionary, Rosedale is credited with numerous industry firsts: container growing, customized soil mixes, plant patenting, nationwide shipping, and consumer branding.

In an early brochure, Rosedale said: “We are always looking for new and improved varieties so you can have that ‘something special‘ to attract your customer’s attention.”

Rosedale pioneered container-grown landscaping plants to help plants establish without transplant shock. Previously plants were grown in-ground and dug for shipping. “He realized that it would make it a lot easier to ship plants if they were grown in containers originally,” Tamony said.

The first containers? Metal egg cans from the breadmaking industry, said Nicholas Staddon, a plantsman and consultant who worked for Monrovia for 27 years in sales and as a spokesperson. After moving to plastic, the company eventually introduced the trademark green pot and in the 1960s, launched the first photo plant tags.

In the 1940s, Monrovia began scheduled shipping to garden centers in California and Arizona and cultivated its own direct sales force rather than using brokers, Tamony said. “In the 1950s, we were the first nursery to ship container plants across the whole country. In the ’50s and ’60s Martin Usrey built on Rosedale’s philosophy of what a plant needed to thrive, and he established the research department, which led us to create the custom soil mixes.”Beginning with Pyracantha ‘Rosedale’ in 1941, Rosedale made Monrovia a trailblazer in breeding and patenting. Today, Monrovia has patented or trademarked hundreds of varieties, offers an exclusive collection from plant explorer Dan Hinkley, and builds strong relationships with breeders globally.

“We’ve introduced more plants than anyone else in North America,“ Tamony said, via both breeding and sports discovered in the field.

Monrovia has led with sustainability initiatives as well. In the 1970s, Monrovia became the first grower to recycle irrigation runoff, setting an industry standard that continues today. It was an early adopter of reusing vegetative waste, banning neonicotinoids, adding mycorrhizae into soil, and incorporating integrated pest management (IPM).

What sets Monrovia apart

“Woody ornamentals are our forte, but some of the genera we’re known for are juniper, boxwood, and ilex and flowering shrubs like camellias and roses,” Tamony said. “We are the largest grower of Flower Carpet roses in the country.”

“One of their great programs was with Itoh peonies,” recalled Staddon.

“People had been able to buy tubers since the ’60s, but a Canadian breeder approached us with a tissue culture technique.”

It was expensive, but former CEO Bruce Usrey gave the go-ahead. “It took about three years to get going and it was a rip-roaring success,” Staddon added.

He said they also introduce southern blueberries nationally via tissue-cultured hybrids from Fall Creek Farm & Nursery Inc. in Lowell, Oregon, resulting in the wildly popular ‘Bountiful Blue’.

Because it was produced by tissue culture, it was vigorous and a heavy fruiter. ‘Bountiful Blue’ was a game-changer and quickly became a household name at many nurseries and garden centers.

Growing techniques complement the plant selection. “We prune our plants more frequently and with more care, to produce a fuller plant,” said Tamony. “And we’re known for our topiary craftsmanship — spirals, cones, pompoms, espaliers and patio trees.”

A culture of craftsmanship

Monrovia employees are known as craftsmen, a term coined by Rosedale, because propagators and growers were and are absolute masters of their craft. 

“We feel like the work, it’s an art and science. They work with their head, heart and hands to create beautiful plants,” said Tamony. “That’s something that is very much a part of our culture.”

That philosophy extends beyond the nursery gates. “From the very beginning, Monrovia has been committed to making the whole industry stronger,” says Jonathan Pedersen, president and CEO. “Early technical advances, breakthroughs in plant production and opportunities for professional development weren’t kept secret. It’s a principle we still practice today in production, plant health, marketing and across our company. When we work together it makes us all better. It truly is part of our DNA.”

The investment in both technology and people results in employee longevity. For Tamony, the annual service awards are a highlight. “Every year, I’m amazed at how many people have worked for Monrovia over 30 years,” Tamony said. “There are families where people met their spouse here, their kids work here, or their brother works here.”

Monrovia has increasingly embraced automation to free up craftsmen for skilled work. “We’ve invested in automation, looking at how we can automate steps that don’t require craftsmanship and may lead to repetitive injuries,” said Tamony.

Since implementing TTA Cutting Edge and Flex Sorter systems in California and Oregon, Monrovia has seen remarkable productivity gains, she said. The Cutting Edge processes between 1800–3000 cuttings per hour and can plant more than 2,000 in an hour. This represents a huge leap forward for the nursery in terms of time saved. The Flex Sorter has boosted sorting rates to 900 per hour compared to 184 manually.

In addition, on demand tag printing has cut time spent on labeling in half, as the time consuming task of applying price stickers has been eliminated. Spacing robots now handle the physically demanding work of arranging containers, processing 485 two-gallon plants per hour versus 200 by hand. For five-gallon containers, robots space 384 per hour compared to 100 by hand.

Even with automation, she noted, skilled craftsmen remain essential for operating the equipment.

Looking ahead: the next century

As Monrovia approaches its centennial, Tamony said the milestone represents a threshold into a new era.

“For a business to be in business for 100 years, you have to keep reinventing,” Tamony said. “What made you successful 50 years ago didn’t make you successful 20 years ago. This year is like a doorway into, ‘What do we need to look at with new eyes?’”

That philosophy is grounded in rigorous consumer research. Each June, Monrovia surveys gardeners about their motivations, purchases, and struggles. The findings inform trend predictions released each September through webinars open to customers and consumers.

Current research reveals key shifts. “Patio culture” is booming, with consumers wanting container gardens featuring edibles, dramatic foliage, and shrubs. There’s growing appetite for unusual edibles — dwarf blueberries, nectarines, and cold-hardy figs, persimmons, and kiwis.

Climate change drives innovation. “Whether you get a lot of water or little water, the climate is changing, and people are looking for plants that can really not just survive the heat, but really thrive in it,” Tamony said. Monrovia is developing zone-five options that are both cold-hardy and drought-tolerant for regions like Utah, Colorado, and the Midwest facing new weather extremes.

Natural landscapes and native plants are trending, but Tamony offers a nuanced perspective: mixing pollinator-friendly natives with climate-appropriate cultivars may be an easier on-ramp for most gardeners than an all-native garden.

Breeding priorities include compact varieties for shrinking gardens, longer-blooming perennials, and breakthrough roses delivering disease resistance and fragrance. The company has expanded perennials and continues developing regional natives, though Tamony noted hyper-local natives are better sourced from local growers.

Pollinator support remains central. The Bee a Winner program has given away more than 8,000 pollinator plants through garden center contests. This year, based on customer fascination with hummingbirds, Monrovia launched a program with downloadable planting plans.

Looking ahead, Tamony said, “How we’re thinking about the future is, ‘How will people be gardening? What will they be looking for and how can we grow that for them?’”

These questions have guided Monrovia for nearly a century — and they promise to keep the pioneering nursery relevant for the next hundred years.

• Founded: 1926
• Co-chairman of the board: Miles Rosedale
• Known for shrubs, trees and perennials.
• Contact: 8441, 13455 SE Lafayette Hwy, Dayton, OR 97114, 800-999-9321
• Online: Monrovia.com
• Nursery Guide 29 listings

From the December 2025 issue of Digger magazine | Download PDF of article

Read the other Nursery Country 2025 grower profiles:
Columbia Nursery | Ekstrom & Schmidt Nursery | Heritage Seedlings & Liners

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