The Trichome Society
Grow science,
worn.
Minimal apparel built on real grow data: VPD, light, climate. For growers who know their numbers.
Drop 01 · out now
Drop 01
Three shirts. One chart.
Every line on these back prints is calculated, not copied: vapor pressure deficit across temperature and humidity. Front: the mark. Back: the math.
- Heavyweightorganic cotton, oversized high-neck fit
- Printed on demandin the EU, nothing is overproduced
- Real dataMagnus–Tetens, air VPD in °C and kPa
Free shipping across the EU from €79. Follow @thetrichomesociety for new drops.
The chart behind the shirts
Find your zone.
Set your room’s temperature and humidity. The dot shows where your plants are: too humid, clones, veg, flower or too dry.
Want the leaf-temperature version? Open the full VPD calculator.
Why VPD
The most underrated number in your grow.
Vapor pressure deficit tells you how hard the air pulls water out of your plants. Get it right and they breathe, drink and grow. Get it wrong and they shut down.
Grow science
Know your numbers.
What is VPD?
The gap between how much water the air could hold and how much it does.
Read + calculator02Ideal humidity
There is no single right humidity. The table for your temperature and stage.
Read03PPFD guide
Watts tell you what the lamp uses. PPFD tells you what the plant gets.
Read04Dew point & mold
The water in your air doesn’t leave at lights-off. When humidity turns into bud rot.
Read + calculator05Leaf vs. air
Under LEDs your leaves run cooler. Your real VPD is lower than you think.
Read06Free VPD chart
Every VPD value on one A4 page. Print it, tape it to your tent.
Download PDF
Meet the mark.
Three stalked trichomes, seen through a loupe. The moment you lean in and look closer. That’s what this brand is about.