
Episode 151: Light, Spectrum, and Plant Signals — A Practical Guide with Dr. David Hawley part 1
In this conversation, Tad and Dr. David Hawley (Chief Science Officer at Fluence) unpack what really matters when dialing in your lighting strategy for cannabis and other high-value crops. They get deep into how plants perceive light, what “good spectrum” actually means, and how to think about intensity, uniformity, and plant response in a more scientific (and practical) way.
Topics covered include:
Understanding Daily Light Integral (DLI) and how it relates to plant metabolism
When to use far-red and what to expect from it
The truth about UV lighting and secondary metabolite production
Managing leaf temperature and avoiding hidden stress from high PPFD
How fixture placement and uniformity impact yield and morphology
Using dimming strategies through different growth stages
Why overemphasizing spectrum specs can distract from the real gains
Practical steps for mapping your grow and verifying performance
David also shares insights on under-canopy lighting, canopy architecture, and the future of horticultural light design, offering takeaways for both commercial cultivators and serious home growers.
Resources mentioned:
KiS Organics Living Soil & Nutrients





