Vineyard Underground

In this conversation, Fritz continues his deep dive with Thijs Verschuuren of Herman J. Wiemer, exploring practical baby steps toward biodynamic and organic vineyard management. Thijs walks through how he structures a non-systemic spray program in a high-disease-pressure region, breaking down critical spray timing, coverage strategies, and why he treats bloom and cap fall as "non-negotiable" spray windows.
They discuss how Thijs combines copper, sulfur, plant teas, biologicals, and newer tools like chitosan-based fungicides and kaolin clay to target downy mildew, black rot, powdery mildew, and leafhoppers, while staying within strict copper limits and managing livestock safety.
Fritz and Thijs also cover biodynamic teas, how forecasting and 48‑hour brews fit into a preventive program, and why daily scouting and mapping disease "pockets" are essential. The conversation concludes with canopy management, pruning, mechanization, and thoughtful leaf removal that maintain disease control without sacrificing the acidity and fruit quality of Riesling and Chardonnay on the path to Demeter certification.
In this episode, you will hear:
Why spray timing and coverage matter more than product choice in organic and biodynamic programs

How to integrate copper, sulfur, oils, chitosan, and kaolin clay while respecting label limits and site conditions

Practical strategies for managing downy mildew, black rot, and powdery mildew with a mostly protectant toolbox

How biodynamic teas and preparations fit into a preventive, weather‑driven vineyard health program

Daily scouting, mapping, and localized spraying as core tools to limit disease spread and input use

Follow and Review:
If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.
Today's Guest:  
Thijs Verschuuren is the Director of Vineyard Biology & Biodynamic Specialist at Hermann J. Wiemer Vineyard in upstate New York. 
Connect with Thijs at https://www.wiemer.com/ or follow him at hermannjwiemer.
Resources:
Come grow with Fritz at https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.
Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.
Episode Sponsor:
Today's episode was brought to you by Clemens and HydroGeo Environmental.
Thank you to Clemens Technologies for sponsoring today's episode. Clemens Technologies is the market leader in machinery for all elements of vineyard management. Visit https://www.clemens-online.com/us/ and provide the code UNDERGROUND to receive 5% off your order of in-stock machinery. Or reach out to Thomas Clemens directly at thomas@clemens-america.com with any questions.
Thank you to HydroGeo Environmental for sponsoring today's episode. For over 20 years, Bubba Beasley and his team have helped vineyard growers with site assessments, mapping, soil and groundwater evaluations, and optimal vineyard layouts. Using the latest technology and industry expertise, HydroGeo brings clarity to even the most complex landscapes. Visit HydroGeoEnvironmental.com and mention the Vineyard Underground podcast for a special discount on your service.
Episode Credits
If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

In this episode, we dig into what it really looks like to take manageable, real-world steps toward biodynamic and organic winegrowing with Thijs (Taze) Verschuuren, Director of Vineyard Biology and biodynamic specialist at Hermann J. Wiemer Vineyard in New York's Finger Lakes.
We follow Thijs's path from European wine regions to the Finger Lakes and unpack the make-or-break 2018 season. That side‑by‑side contrast pushed the team to fully embrace biodynamics and pursue Demeter certification.
We break down biodynamics in practical terms: treating the farm as a living, self-sustaining organism that integrates cover crops, livestock, compost, and on-farm preparations to build resilience from the soil up. Then we zoom into vineyard floor management as an accessible entry point, showing how diverse clover mixes, smarter mowing vs. crimping decisions, and minimal cultivation helped boost soil organic matter from ~1.7% to over 6% in about seven years — one "baby step" at a time.
In this episode, you will hear:
Why a wet 2018 season pushed Hermann J. Wiemer to deepen its biodynamic commitment

How biodynamics differs from organics in philosophy and farm design

A practical framework for cover crops (especially clovers) to build organic matter and vine resilience

When to mow, when to crimp, and why there's no "set-it-and-forget-it" spray or floor program

Baby-step starting points: soil testing, cover cropping, and small-scale animal integration

Follow and Review:
If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.
Today's Guest: 
Thijs Verschuuren is the Director of Vineyard Biology & Biodynamic Specialist at Hermann J. Wiemer Vineyard in upstate New York. 
Connect with Thijs at https://www.wiemer.com/ or follow him at hermannjwiemer.
Resources:
Come grow with Fritz at https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.
Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.
Episode Sponsor:
Today's episode was brought to you by Clemens and HydroGeo Environmental.
Thank you to Clemens Technologies for sponsoring today's episode. Clemens Technologies is the market leader in machinery for all elements of vineyard management. Visit https://www.clemens-online.com/us/ and provide the code UNDERGROUND to receive 5% off your order of in-stock machinery. Or reach out to Thomas Clemens directly at thomas@clemens-america.com with any questions.
Thank you to HydroGeo Environmental for sponsoring today's episode. For over 20 years, Bubba Beasley and his team have helped vineyard growers with site assessments, mapping, soil and groundwater evaluations, and optimal vineyard layouts. Using the latest technology and industry expertise, HydroGeo brings clarity to even the most complex landscapes. Visit HydroGeoEnvironmental.com and mention the Vineyard Underground podcast for a special discount on your service.
Episode Credits
If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

We mark a major milestone with our 100th episode by stepping back to look at where the vineyard industry has been and where it's headed next. Fritz walks us through what's in, what's out, and what's coming for growers who want to stay profitable and resilient.
We start with the changing economics of grape growing. Planting Cab, Merlot, or Syrah on speculation no longer pencils out in an oversupplied market. Instead, we focus on matching varieties to region, climate (including future climate), water availability, disease pressure, and a clearly defined sales channel. 
From there, we connect vineyard design to labor and equipment realities. We move away from high‑input, labor‑intensive layouts and toward simpler, mechanization‑friendly systems that can eventually support autonomous tools. 
We then turn to the vineyard floor, moving from bare soil and blanket herbicide programs to living systems built around cover crops, reduced tillage, and grazing with sheep. By the end, we have a clear picture of the practices that are fading, the ones gaining momentum, and the directions we can embrace to stay ahead in the next decade of grape growing. 
We look forward to the next 100 episodes!
In this episode, you will hear:
Planting on speculation is out; committed buyers and clear sales channels are in

Variety selection must fit climate, water, disease pressure, and market identity

High-input, labor-intensive designs are giving way to mechanization‑friendly trellis systems and layouts

Soil and irrigation should be managed as one integrated system

Living vineyard floors are key to long‑term soil health

Follow and Review:
If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.
Resources:
Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.
Come grow with Fritz at https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.
Episode Sponsor:
Today's episode was brought to you by Vigneron Toy Store and HydroGeo Environmental.
Thank you to Vigneron Toy Store for sponsoring today's episode. Vigneron Toy Store specializes in Harvesters, Sprayers, Frost Mitigation Equipment, Canopy Management Trimmers, and more. As grape growers themselves, they can expertly help you determine the best equipment for your specific vineyard needs. And, as a special offer for our podcast listeners, you can save 5% on in-stock machines by entering the promo code Underground on the contact form at vignerontoystore.com.
Thank you to HydroGeo Environmental for sponsoring today's episode. For over 20 years, Bubba Beasley and his team have helped vineyard growers with site assessments, mapping, soil and groundwater evaluations, and optimal vineyard layouts. Using the latest technology and industry expertise, HydroGeo brings clarity to even the most complex landscapes. Visit HydroGeoEnvironmental.com and mention the Vineyard Underground podcast for a special discount on your service.
Episode Credits
If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

Dr. Katie Gold and Dave Combs from Cornell University join Fritz to unpack one of the most confusing topics facing winegrape growers today: how biological fungicides truly fit into a spray program.
Katie explains how the Cornell grape pathology program has expanded rapidly, moving from strictly conventional efficacy trials into extensive work with biologicals as more of these products come out of R&D pipelines. She outlines why growers can't rely on "the next new conventional" anymore and how biologicals are becoming essential tools for sustainable disease management and resistance stewardship.
Dave brings decades of field experience and shares how his initial skepticism about biologicals shifted after seeing modern products perform on highly disease‑prone varieties in one of the toughest vineyards for powdery mildew, downy mildew, black rot, and bunch rots. Together, they walk through what "compatibility" really means and why water pH, formulation, and whether an organism is alive or dead matter far more than many growers realize.
Listeners learn why mixing biologicals and conventionals in the same tank often provides no added control (and may waste money), where negative interactions can show up, and why tightening intervals and understanding infection periods is critical when working with protectant biologicals. 
In this episode, you will hear:
Why more new products in the pipeline are biologicals rather than conventional chemistries
How Cornell's high‑pressure pathology vineyard reveals the real-world limits and strengths of biologicals
Why many biologicals are strictly protectants and must be applied before significant disease is present
How tank mixing biologicals with conventionals can reduce cost-effectiveness without improving control
Why understanding water chemistry, pH, and product formulation is now an essential spray-program strategy
Follow and Review:
If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.
Resources:
Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.
Come grow with Fritz at https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.
Today's Guest: 
Dr. Katie Gold is an Assistant Professor of Grape Pathology at Cornell University, where she holds primary research and extension responsibilities for grape disease management in New York State.
Dave Combs is a Research & Extension Support Specialist II in Dr. Katie Gold's Grape Pathology Laboratory at Cornell AgriTech in Geneva, New York, with 20+ years of experience in chemical and cultural grape disease management.
Connect with Katie: https://cals.cornell.edu/kaitlin-gold
Visit the Gold Lab to view their research work: https://blogs.cornell.edu/goldlab/
Episode Sponsor:
Today's episode was brought to you by Shellt Grow Tubes and Vigneron Toy Store 
Thank you to Shellt Grow Tubes for sponsoring today's episode. Shellt makes the ultimate grow tubes for grape vines and orchard trees. Their grow tubes are reusable, recyclable, and designed to grow with your vineyard by clicking together for taller or wider coverage. I exclusively recommend Shellt Grow Tubes to the growers I work with. Visit https://www.shellt.us/ and order with the code UNDERGROUND to save 15% off all online orders, plus free shipping within the continental United States.
Thank you to Vigneron Toy Store for sponsoring today's episode. Vigneron Toy Store specializes in Harvesters, Sprayers, Frost Mitigation Equipment, Canopy Management Trimmers, and more. As grape growers themselves, they can expertly help you determine the best equipment for your specific vineyard needs. And, as a special offer for our podcast listeners, you can save 5% off in-stock machines by entering the promo code Underground on the contact form at vignerontoystore.com.
Episode Credits
If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.

Small vineyard decisions made early in the season can create major ripple effects later in the year, and in this episode, Fritz breaks down three vineyard management tasks that are frequently skipped, delayed, or underestimated despite their outsized impact on vine health, fruit quality, and long-term vineyard performance.
Fritz focuses first on shoot thinning and explains why timing is everything. He walks through the economic and practical advantages of thinning early, including improved spray penetration, better airflow, easier hand harvesting, and even reduced pruning labor during dormancy. 
He then explains why bloom and veraison sampling windows are critical for understanding nutrient status and preventing deficiencies before they become costly problems. Lastly, he tackles water stress monitoring and the common misconceptions surrounding vineyard stress. 
Listen in for practical ways growers can monitor irrigation effectiveness, evaluate soil moisture, and avoid relying solely on visual assumptions about vine stress levels. Remember, better data leads to better vineyard decisions.
In this episode, you will hear:
Early shoot thinning can improve fruit quality, airflow, spray coverage, and long-term pruning efficiency

Delayed shoot thinning increases labor costs and creates more winter pruning wounds susceptible to trunk disease

Tissue sampling at bloom and veraison helps growers identify nutrient deficiencies before productivity suffers

Leaf blade sampling may provide more reliable nutrient data than petiole sampling for many nutrients

Water stress should be monitored with both field observation and measurable soil moisture data

Excess vigor, nutrient imbalance, weather extremes, fungal disease, and insects can all contribute to flower browning during bloom

Follow and Review:
If you enjoyed this episode, be sure to follow the podcast and leave a 5-star review on Apple Podcasts! Your support helps us reach more listeners. 💜 Click the '+' in the top right corner of Apple Podcasts to follow now.
Resources:
Get Fritz's Shoot Thinning, Tissue Sampling, and Plant Stress resources available for podcast listeners at VirtualViticulureAcademy.com/tasks.
Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.
Episode Sponsor:
Today's episode was brought to you by SensorInsight and Clemens Technologies.
Thank you to SensorInsight for sponsoring today's episode. SensorInsight is a leader in vineyard soil moisture and weather monitoring. SensorInsight designs state-of-the-art, remote satellite monitoring of soil moisture and weather, bringing actionable information for your vineyard operations straight to your phone, with real-time data so you can best decide when to turn on your irrigation, how long to run the system, and learn how the dynamics of soil moisture can change over a given season. Visit them today at https://sensorinsight.io. And don't forget to mention the code Underground to receive a discount on your SensorInsight solution.
Thank you to Clemens Technologies for sponsoring today's episode. Clemens Technologies is the market leader in machinery for all elements of vineyard management. Visit https://www.clemens-online.com/us/ and provide the code UNDERGROUND to receive 5% off your order of in-stock machinery. Or reach out to Thomas Clemens directly at thomas@clemens-america.com with any questions.
Episode Credits
If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.