Jeremy Warren, Director of Plant Genetics at Curaleaf – Interview Series

Just about any cannabis cultivator will admit that planting seeds and harvesting crops is only part of the job. A significant portion of a grower’s daily responsibility involves keeping plants healthy and free of molds, pests, yeasts, and bacteria—threats that can damage a crop and trigger failures during mandatory lab testing. An issue as seemingly minor as a localized Aspergillus outbreak can spread rapidly across multiple grow rooms, posing serious operational headaches and potential health risks for consumers.

To take a closer look at plant health, disease prevention, and the research surrounding a particularly lethal plant pathogen, mycannabis.com spoke with Jeremy Warren, Director of Plant Genetics at Curaleaf.

When obtaining your PhD in Plant Pathology/Phytopathology from the University of California-Davis, what were the most interesting and worthwhile courses you took? How did those courses in particular help you throughout your career?

Two of the most interesting and worthwhile courses I took as a graduate student were Plant Bacteriology taught by Dr. Bruce Kirkpatrick and Plant Virology taught by Dr. Bryce Falk.

Both of these classes and professors instilled a solid foundation in root cause analysis and really helped with my understanding of how to pick up on all of the things data tells us about a system. Specifically for cannabis it was the techniques and critical thinking learned in Plant Virology that gave me the foundation to be able to crack the hop latent viroid puzzle.

Developing the tools in grad school to become a great problem solver through these classes and the program in general had perhaps the most worthwhile impact on my career and I still use these tools today at Dark Heart.

How were the sciences behind cannabis and hemp plants part of your studies at UC-Davis?

When I was in grad school there was really zero university research being done on hemp or cannabis outside of a single government lab in Mississippi. Luckily the tools to do the research are the same so all of the knowledge gained from studying other plants is applicable to the research we at Dark Heart are doing now in cannabis. This is actually one of the things that makes cannabis research so exciting: the wealth of information yet to be discovered.

Prior to joining the cannabis industry, what roles did you hold in biotech and similar fields? What were the most useful skills in business and team leadership during those roles?

Before joining Dark Heart, I served as President and CEO of the biotech start-up, Astrona Biotechnologies. That role taught me how to lead a scientific team focused on uncovering novel discoveries, an experience that translates directly to my work at Dark Heart, where we develop and evaluate new cannabis strains.

Another facet of helping cofound a startup was translating the scientific discoveries into business use cases. As part of this process our company was admitted to IndieBio, a biotechnology startup incubator similar to Y combinator. This experience really helped me understand how to look at technology through a business lens and understand that the pace of scientific discovery in industry has to be much faster and have an immediate impact to be most successful.

When did you decide to first start working in the cannabis industry? How did you envision that you could utilize your extensive PhD studies and prior professional experience in cannabis industry roles?

I started in a traditional agriculture role but I’ve been a fan of cannabis for a long time. When there was an opportunity to move to Dark Heart, I jumped on it and haven’t looked back since.

Before joining Dark Heart and before my role as CEO for the start-up, I worked in the Department of Plant Pathology at UC Davis and served as a Biological Science Laboratory Technician for the USDA. All of these roles helped me build a strong foundation in plant science, genetics, and research that I use in my position now as Director of Plant Genetics for Curaleaf.

What are your favorite parts of serving as Director of Plant Genetics for Curaleaf? What aspects of research and development do you regularly do?

My favorite part is the core of the work we do with Dark Heart: pushing the limits of the cannabis plant to see what it’s capable of. Our goal is to deliver one-of-a-kind genetics to cannabis fans and give them a sensory experience like no other.

We like to say Dark Heart is grown with culinary precision. Every decision we make is about flavor, aroma and experience. All of our strains are the result of rigorous testing so our customers know when they pick up a Dark Heart product, they are in for a truly unique sensory experience.

One of the more enjoyable parts of my job is providing a space where those who work for me are enabled to make discoveries. Sometimes people forget R&D is a collaborative process. Giving people who are excited to take cannabis to the next level, the space to develop and discover things we haven’t even thought about doing, is truly rewarding and in my opinion leads to the best new discoveries.

What does serving as that role for one of the largest cannabis companies in America entail? With so many strains and products and SKU’s, how do you ensure that Curaleaf stays ahead of its competition when it comes to plant genetics and strain offerings?

Our goal is to set a new standard with cannabis across all of our products so I am honored to be in this role and use my expertise to lead that mission. With Dark Heart, for instance, we are pushing cannabis toward a more refined, intentional, palate-driven future.

How has your role evolved since first working with Curaleaf? As the company and the greater American cannabis industry expand, how have your duties changed over those years?

The cannabis world has evolved so much since I first started working with Dark Heart.

When Dark Heart Nursery started in 2007, it was like the Wild Wild West. The nursery was rebuilt twice after burglaries and violence, and it operated continuously through federal raids and shifting regulations from 2007–2024. Even with those major obstacles, the nursery spent nearly 20 years serving growers before launching its own consumer products.

Now that we’re a part of Curaleaf and the wider cannabis industry continues to mature, we’re seeing more traditional agriculture methods being brought into the industry. More plant science principles are being applied to cannabis and more resources are being put into R&D, which is very exciting.

But even as the industry evolves, our goals remain the same: we continue to be dedicated to providing genetics with unmatched quality and purity.

How in detail have you researched the hop latent viroid, and how does this viroid impact cannabis and hemp crops specifically?

Our group is the team that discovered that hop latent viroid was the cause of cannabis dudding disease. (There are some fun names for it like “the itis,” “dudders,” and “yellow head.”) As mentioned earlier it was the training I received through my PhD work that allowed us to determine the right scientific methods to use in order to elucidate the cause of this disease that was causing ~20%+ yield losses in grows throughout the world. We were the first group to discover hop latent viroid as a pathogen of cannabis, develop a test to determine if a plant was infected, and then offer that test to the entire cannabis community so the industry as a whole could eradicate it. We made the choice to share the discovery as cleaning up all of the known cannabis germplasm is a win for the industry and patients as a whole.

What are some productive steps and methods that cultivators can take to minimize the risk of an HpLVd outbreak? What are some common causes of an outbreak to begin with?

The steps for cleaning a facility are well known at this point. Through a regime of DNA based testing of your mother plants and strict adherence to tool sanitation, a facility can become viroid free. The most common cause of hop latent viroid outbreaks is bringing in new genetics from third-party sources. Always ensure your partners are testing for the viroid and always test any new material coming into your facility.

How can research and development into cannabis science and genetics improve and advance in the future? As cannabis becomes more normalized and federally permitted, how do you think those sweeping changes could help advance cannabis research?

Research and development in cannabis–like we’re doing at Dark Heart and our wider Curaleaf brands–is essential because it pushes the plant and industry forward. We are at a unique time as cannabis becomes more normalized and legitimized in our culture, bringing in new fans and pushing the industry to keep innovating.

I am proud that our team at Dark Heart is a leader in this space. We pride ourselves on showcasing the craft of cannabis, helping people appreciate the possibilities of this plant and the experience it provides.

Thank you for joining us, Jeremy! For more information on Curaleaf, please visit its website.