In Pursuit of Roses: A Master Rosarian's Insights on Modern Roses, Diversity, and Disease Resistance

Roses have a reputation for being high-maintenance, but the best rose breeders are chasing a different future: roses that bloom for months, shrug off disease, and succeed for everyday gardeners. We sit down with Dr. David Zlesak, a master rosarian and rose breeder, to unpack how roses went from ancient treasures traded across regions to the modern plants you see at big box stores and independent nurseries.

We dig into the deep history of cultivated roses, including how genetics is rewriting origin stories and how repeat-bloom traits from historic Chinese roses helped shape today’s garden varieties. Then we zoom into what buyers want now, from cut-rose goals like longer shelf life, fewer thorns, and more fragrance, to shifting tastes in flower form influenced by everything from rose shows to English-style, old-fashioned blooms.

The conversation turns practical and science-forward: black spot disease resistance, why multiple races make durability hard, and how stacking resistance genes and developing useful genetic markers can speed up breeding progress. We also explore environmental stress, including heat tolerance and winter hardiness, and how the American Rose Trials for Sustainability (ARTS) tests roses regionally to identify truly tough, low-input performers. Finally, David shares how the rose business has changed, why Knock Out roses reset the market’s expectations, and the career mindset that keeps him moving: ask what if, focus on market-limiting traits, and build a community of collaborators.

If you love gardening, plant breeding, or sustainable horticulture, subscribe for more conversations like this, share the episode with a fellow rose grower, and leave a review so more listeners can find Plants, People, Science.

Read more from David Zlesak  - 

Plant Science Students’ Thinking Styles and Multiple Intelligences Based on Major, Gender, and Course

The Effects of Short-term Drying on Seed Germination in Rosa

Northern Accents® ‘Lena’, ‘Ole’, ‘Sigrid’, and ‘Sven’: Four Cold-hardy Polyantha Rose Cultivars from the University of Minnesota Woody Landscape Plant Breeding Program

Send us Fan Mail

Learn more about the American Society for Horticultural Science (ASHS) at  https://ashs.org/.
HortTechnology, HortScience and the Journal of the American Society for Horticultural Science are all open-access and peer-reviewed journals, published by the American Society of Horticultural Science (ASHS). Find them at journals.ashs.org.

Consider becoming an ASHS member at https://ashs.org/page/Becomeamember!

You can also find the official webpage for Plants, People, Science at ashs.org/plantspeoplesciencepodcast, and we encourage you to send us feedback or suggestions at https://ashs.org/webinarpodcastsuggestion.

Podcast transcripts are available at https://plantspeoplescience.buzzsprout.com.

On LinkedIn find Sam Humphrey at linkedin.com/in/samson-humphrey. Curt Rom is at https://www.linkedin.com/in/curt-rom-611085134/. Lena Wilson is at https://www.linkedin.com/in/lena-wilson-2531a5141/.

Thank you for listening!

...