The Queen of Flowers: From HVAC Engineer to Peony Scientist with Dr. Emily Zhou
S01:E06

The Queen of Flowers: From HVAC Engineer to Peony Scientist with Dr. Emily Zhou

Blacksburg, Virginia
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Episode description

Blooms and Beyond - Season 1, Episode 6

Episode Title:

“The Queen of Flowers: From HVAC Engineer to Peony Scientist with Dr. Emily Zhou”

Episode Description

What happens when an HVAC engineer falls in love with plants and earns a PhD studying one of the world’s most beloved flowers? In this episode, Dr. Ping Yu sits down with Dr. Emily Zhou, assistant professor at the University of Central Missouri, to explore her remarkable journey from engineering in China to pioneering peony research in the United States.

Peonies have captivated cultures for over 4,000 years—from ancient Chinese poetry to modern American weddings. But growing these stunning “queens of the flower world” isn’t easy. Dr. Zhou’s groundbreaking research reveals how growers can slash production time from 18 months to just 5-6 months using the right combination of chilling treatments and plant growth regulators. Whether you’re a commercial producer looking to hit the Valentine’s Day market or a plant enthusiast dreaming of growing peonies in the South, this episode is packed with practical wisdom and enchanting plant stories.

Discover why peonies need cold to bloom, how a $120 yellow peony in a one-gallon pot reflects the plant’s precious nature, and what it means when a plant scientist says she still thinks like an engineer. This is plant power at its finest!

Listen Time: ~46 minutes

Consulte las Notas del Programa

🌸 This Episode is Sponsored by AFE

This episode in our first season is made possible through an educational grant from the American Floral Endowment, whose research priorities helped shape the topics that are featured. To learn more about AFE and access their research and educational resources, visit their website at endowment.org.

Featured AFE Resource: DLI Maps and Free DLI Poster — Understanding Daily Light Integral is essential for greenhouse production. Access these free tools at endowment.org.

In This Episode

Featured Guest

Dr. Emily Zhou — Assistant Professor, University of Central Missouri, Department of Agriculture. Former R&D Scientist at Bowery Farming (indoor vertical farm). PhD research focused on herbaceous peony production, vernalization, and plant growth regulators. Background in HVAC engineering with 10+ years industry experience before transitioning to horticulture.

Main Topics

Dr. Zhou’s Unique Journey (01:02 - 07:40)

  • From HVAC engineer in China and European companies to plant scientist
  • Arriving in the U.S. in 2002 and discovering Virginia Tech’s horticulture program
  • Filling the gap: taking undergraduate and graduate courses to build plant science foundation
  • The moment of asking “What do you love? What is your passion?”
  • How engineering and horticulture came together in controlled environment agriculture

Why Peony Is Her Favorite Plant (07:40 - 10:10)

  • “I gained my Doctor of Philosophy out of that”
  • Four years of PhD research requiring data collection through every holiday season
  • The beauty of watching a crown develop into the most beautiful flower
  • Horticultural therapy: plants adding value to mental and spiritual wellbeing

Peony History: From China to the World (11:18 - 14:00)

  • Native to China with 3,000-4,000 years of cultivation history
  • Appears in ancient Chinese poetry as a flower of love
  • Medicinal uses: white root peony and red root peony for herbal medicine
  • Peak cultivation during Tang and Song dynasties around the Yellow River
  • Luoyang’s 1,300-year-old peony gardens still thriving today
  • Spread to Japan, then Europe in late 1800s, then America in early 19th century

Why Peonies Are Expensive (14:00 - 17:30)

  • Limited cultivars adapted to southern climates
  • Yellow peony cultivar: $120 for a small one-gallon pot (2017)
  • Cut flower value: over $6 per stem for weddings
  • American Peony Society registers thousands of herbaceous cultivars
  • Tree peony, herbaceous peony, and Itoh hybrids offer diverse options
  • Requires skill to grow well—“queen of the flowers” for a reason

Cultural Significance (16:55 - 18:20)

  • Top 10 most famous flowers in China, representing prosperity
  • Tree peony is China’s national flower
  • In the U.S.: symbolizes freedom, pioneering spirit, and true love
  • Used extensively in weddings
  • “It’s not just the plant, it’s everything about the plant”

The Science of Vernalization (18:20 - 25:30)

  • Peonies are geophytes (underground storage organs) like tulips and daffodils
  • Underground crown develops buds during summer after flowering
  • Buds set by September/October—critical not to cut foliage too early
  • Without adequate chilling, plants grow shoots but no flowers
  • Natural chilling depends on weather; controlled chilling provides consistency
  • Zone 6 and below: natural chilling sufficient
  • Zone 7: borderline—may need supplemental chilling

Forcing for Valentine’s Day (22:05 - 28:10)

  • Controlled chilling: 3 weeks (21 days) at 40°F is sufficient
  • Sarah Bernhardt cultivar: #1 cut flower worldwide, 50% of peony market
  • After chilling, greenhouse forcing produces flowers in about 2 months
  • Netherlands is biggest producer; U.S. growers in Oregon, Washington, Great Lakes region
  • Southern growers must use forced chilling to hit Valentine’s market

Shortening Production with GA3 (28:11 - 31:15)

  • Traditional containerized production: 18 months for marketable plants
  • Gibberellic acid (GA3) can replace some chilling requirement
  • Ideal concentration: 100 parts per million, applied as drench
  • Best timing: one week after finishing chilling, when moving to greenhouse
  • Result: Production shortened to 5-6 months (Valentine’s supply: 3-4 months)
  • Cost: less than 10 cents per pot
  • “You can do a thousand pots in one day”

Plant Retardants for Compact Plants (31:17 - 39:50)

  • Problem: Heavy flower heads droop, especially in rain/wind
  • Shipping/handling issues: tall stems crack, expensive plants unsellable
  • Solution: Plant growth retardants (uniconazole, paclobutrazol)
  • Uniconazole more effective than paclobutrazol for herbaceous peonies
  • Application: 15 ppm uniconazole, 12 oz drench per one-gallon container
  • Benefits: More compact, stronger stems, greener foliage, more marketable
  • Apply after chilling—not as pre-plant dip (preserves fungicide treatment)
  • Drench method best: ensures uniform application across variable plant sizes

Controlled Environment Agriculture (39:54 - 43:15)

  • Few people doing CEA when Dr. Zhou started her PhD
  • Postdoc: Built indoor vertical farm, conducted hydroponic research
  • Industry experience at Bowery Farming as R&D scientist
  • Why many vertical farms have failed: “We don’t know enough”
  • Engineers want universal systems; plant scientists know each plant needs different conditions
  • Returned to academia to train next generation of growers and researchers

Key Highlights

  • Dr. Zhou’s PhD took 4 years because peony research requires waiting a full year between trials
  • Sarah Bernhardt peony occupies 50% of the worldwide cut flower peony market
  • GA3 treatment can reduce peony production from 18 months to 5-6 months at less than 10 cents per pot
  • Uniconazole drench at 15 ppm creates compact, marketable plants with stronger stems
  • Zone 7 is the “borderline”—growers there may need both GA3 and forced chilling
  • China has cultivated peonies for 3,000-4,000 years; tree peony is China’s national flower
  • The Netherlands is the world’s biggest peony producer; U.S. production centers in Pacific Northwest and Great Lakes

Key Quotes

“I gained my Doctor of Philosophy out of that… I took so long a time and so much effort on this. And it’s rewarding. It is such a beautiful plant.” — Dr. Emily Zhou

“They are speaking two different languages, but I know both of them.” — Dr. Emily Zhou, on bridging engineering and plant science

“It’s not just the plant, it’s everything about the plant.” — Dr. Ping Yu, on plant power

“We don’t know enough. And my idea is going back to academia being a professor.” — Dr. Emily Zhou, on why vertical farms struggle and why education matters

“You just learn the things, you never know when one day you can use them.” — Dr. Emily Zhou

Educational Highlights

What is Vernalization?

Vernalization is the process where plants require a period of cold temperatures to trigger flowering. For peonies, this means exposure to temperatures around 40°F (4°C) for several weeks. Without adequate chilling, peonies will grow vegetative shoots but won’t produce flowers.

Key Plant Growth Regulators for Peony Production

| Chemical | Function | Concentration | Application | |–––––|–––––|—————|———––| | Gibberellic Acid (GA3) | Replaces some chilling requirement, promotes flowering | 100 ppm | Drench, after chilling | | Uniconazole | Growth retardant—compact plants, stronger stems | 15 ppm | Drench, 12 oz/pot | | Paclobutrazol | Growth retardant (less effective on peonies) | Variable | Drench |

Hardiness Zone Guide for Peony Chilling

  • Zone 6 and below: Natural chilling sufficient
  • Zone 7: Borderline—may benefit from GA3 + forced chilling
  • Zone 8+: Requires forced chilling in cold room (40°F for 3 weeks minimum)

Peony Types

  • Herbaceous Peony: Dies back to ground each winter, most common for cut flowers
  • Tree Peony: Woody stems persist; China’s national flower
  • Itoh Peony: Hybrid of tree and herbaceous; best characteristics of both

Resources & Links

Connect with Dr. Emily Zhou:

  • LinkedIn: Search “Emily Zhou University of Central Missouri”
  • University of Central Missouri, Department of Agriculture

Research Publications:

  • Virginia Tech Extension publications on peony production and GA3 application
  • (Links to be added in show notes at bandbpod.com)

AFE Resources for This Episode:

  • DLI Maps: Interactive Daily Light Integral maps to help growers understand light availability by location — visit endowment.org
  • Free DLI Poster: Download AFE’s free Daily Light Integral poster for your greenhouse or classroom
  • Explore more research and educational resources at endowment.org

Organizations Mentioned:

  • American Peony Society (cultivar registration)
  • Battlefield Farms, Virginia (commercial peony production)
  • Bowery Farming (indoor vertical farming)

Visit the Show:

  • Website: bandbpod.com
  • Full show notes and additional resources at bandbpod.com

About Blooms and Beyond

Blooms and Beyond is a podcast that covers plant history, culture, and management through the lens of science. Whether you’re a commercial grower looking for management solutions, a student exploring horticulture careers, or someone who just loves plants and their stories, you’ll find something here for you. Hosted by Dr. Ping Yu from the University of Georgia, each episode features interviews with experts who bring enchanting stories, pioneering research, and practical wisdom from the world of horticulture.

Your Takeaway: When you walk away from each episode, commercial professionals should have at least one piece of advice to help with production, and plant enthusiasts should have one cool fact to share about plants. Because that’s how we spread plant power to a larger audience and make the environment a little bit better.

Credits

Host: Dr. Ping Yu Featured Guest: Dr. Emily Zhou, University of Central Missouri Producer: Rich Braman, UGA Center for Urban Agriculture

Funding Acknowledgement

This episode in our first season is made possible through an educational grant from the American Floral Endowment, whose research priorities helped shape the topics that are featured. To learn more about AFE and access their research and educational resources, visit their website at endowment.org.

Episode Release Date: January 18th, 2026 Episode Length: 46:46

“Till next time, stay healthy and go plants!” 🌸🌿

Episode Tags

Peony, herbaceous peony, tree peony, vernalization, chilling requirement, GA3, gibberellic acid, uniconazole, plant growth regulators, cut flowers, Valentine’s Day, controlled environment agriculture, CEA, vertical farming, HVAC, Virginia Tech, China, floriculture, nursery production

0:06Welcome: Introducing Peonies
1:02Meet Dr. Emily Zhou
2:06From HVAC Engineer to Plant Scientist
4:40Every Step Counts: Combining Skills
7:40Favorite Plant: The PhD Peony
10:10Peony Use in the U.S.: Cut Flowers & Weddings
11:18History: From Ancient China to America
14:00Cultivars & Why Peonies Are Expensive
16:55Plant Power: Cultural Significance
18:20Vernalization: The Science of Chilling
22:05Forcing for Valentine's Day: 3 Weeks at 40°F
25:34Shortening the Production Cycle
28:11GA3: From 18 Months to 5-6 Months
31:17Plant Retardants: Compact & Marketable
35:45Application Tips: Drench Is Best
39:54Controlled Environment Agriculture Journey
43:18The Future: Peonies in CEA?
44:32Connect with Dr. Zhou
45:04Closing & AFE Resources