Issue #717 - Sunday, January 18, 2026 Hey grower, in today's issue... - What is VPD and Why Do Cannabis Growers Care? VPD is related to the temperature and humidity, and affects how much plants drink. Learn the one principle that makes everything clear.
- The "Problem" of Too Much
Weed - So we have a familiar home grower "problem". The kind you get from following good grow practices... Tell us what to turn it into!
- Apple Fritter Plants looking THICK! Check out one grower's "apple bottom" buds.
- 5 Core Principles to Grow Better Weed - Discover how to improve your next home harvest with 5 quick wins!
- A penny for your thoughts... What is your biggest grow
challenge right now? Let us know here. Next week, we release a free guide with the fix to the top challenge!
Nebula Haze & Sirius Fourside
Co-Founders, GrowWeedEasy.com
"A garden is a grand teacher. It teaches patience and careful watchfulness; it teaches industry and thrift; above all it teaches entire trust." ~Gertrude Jekyll What is VPD and Why Do Cannabis Growers Care? by Nebula Haze What is VPD? VPD = "Vapor Pressure Deficit". VPD tells you how strongly the air is "pulling" water out of the cannabis plant's leaves. Put an Aerolab near your plants to directly measure VPD. VPD affects cannabis plant "transpiration" on the leaves, which is a critical part of photosynthesis which turns light into energy. Poor transpiration can cause unwanted side effects such as stress, slow growth, and over-sensitive plants. High VPD - plants lose water fast, because the air is so dry. - Dry air "pulls" more water out of
leaves.
- Must water more often as the plant drinks a lot.
- Plants prone to stress and tip burn.
Low VPD - plants "drink" water slow, because the air is so humid. - Air is already "full" of water, so doesn't "pull" much from the leaves.
- Must give less water, because water doesn't move well through the plant.
- Plants may droop as if overwatered,
and leaves may curl or get brown scorch marks.
Happy healthy cannabis plants are green and perky Why Do Cannabis Growers Care About VPD? VPD affects transpiration on the leaves, which can affect your cannabis plants in various ways. - how fast plants "drink" water
- water movement through the plant
- nutrient uptake
- growth speed
Measurement of VPD is valid science, and can truly
tell you a lot about your cannabis plants. But... What's More Important than VPD to Weed Plants Remember this, cannabis wants about the same environment as a human. On a practical level, this mental model serves you better as a grower than chasing any particular number on a device. - Warm but not hot, with a gentle breeze.
- If it feels hot, cold, or muggy to
you, it is too hot, cold, or muggy for weed.
- Think beautiful spring or summer day, and you're golden.
If it feels comfortable for you, it's probably good for your plants. Why VPD Obsession is Overrated for Cannabis Growers I feel like lots of growers get obsessed with VPD, in part because companies like AC Infinity and Vivosun (which both make excellent cannabis growing supplies) market VPD-based solutions to growers. But that can leave growers confused if your numbers are "right" and buds are not developing
well, or buds are growing big and tight even though VPD is "out of range". Let me quickly cut through the marketing speak so you know exactly how VPD can be a tool for cannabis growers, but not the be-all-end-all solution. VPD when it comes to home cannabis cultivation: - VPD is a tool, not a panacea - VPD is a tool to help you understand what's going on in the plant. But there is no "perfect" VPD for growing
cannabis because optimal environment depends on several factors (including stage of life).
- Most VPD charts are not based on cannabis - Most "optimal VPD" studies were conducted on plants other than cannabis (often lettuce).
- VPD charts don't consider bud quality - Optimal VPD measurements are typically based on leaf transpiration and stomatal function, not what resulted in the best bud quality in the flowering stage for cannabis
plants. Sometimes the tightest, smelliest, most potent buds develop in conditions outside of recommended VPD levels.
Follow what works to grow weed - Cannabis rewards you for keeping your environment in the right ranges (70-85°F/20-30°C, 40-60% RH at first, and 50% RH or less after buds form if possible). That might not result in the "correct" VPD, according to whatever chart you're looking at, for whatever plant it was tested
on, but this proven range is what home growers have found produces the best weed growth and bud density/potency/smell/yields. Chart 1 - Best temperature for cannabis plants. A cheap laser temperature gun lets you point at any spot and instantly check the temperature, so you know how the leaves or buds are "experiencing" heat. These devices are so nifty. I highly recommend getting one simply because it's fun to be able to point at things and see the temperature in real time. Instantly check the temperature of leaves and buds with a temperature gun. Chart 2 - Best humidity for cannabis plants. An Aerolab or similar device makes it easy to monitor the environment. Get the environment right while buds are forming, and cannabis plants reward you with epic bud quality. Conclusion: VPD Matters, but don't obsess over it As long as you keep your temperature and humidity in range, especially as buds are forming, you can rest assured you're giving your plants exactly what they need. Proven Environment = Better Buds For most home growers, a consistent environment that feels comfortable to you keeps your grow in the "sweet spot". More coming next week, including a simple way to keep your plants happy and pristine without any gadgets. Happy Growing,
Nebula Haze GrowWeedEasy.com
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The "Problem" of Too Much Weed
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So we have a familiar home grower "problem". The kind you get from following good grow practices. More weed than we can smoke! Instead of letting it sit in jars, we want to turn it into step-by-step video guides you can copy at home. What should we make
first? - Edibles
- Canna Caps
- Hash (dry ice, bubble...)
- Tinctures
- Rosin
- Something else?
Hit reply and tell us what you want to see! (Our goal is to make sure most growers end up in this
situation)
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Apple Fritter plants with "Apple Bottom" buds
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These are Apple Fritter plants from Seed Supreme seeds. Just finishing up has about 2 more weeks. ~Kenneth
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5 Core Principles to Grow Better Weed
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Follow these universal principles to grow better weed at home. - Start with Extraordinary Genetics – Why? This ensures plants work with you instead of against you. Good seeds grow good weed with your desired effects and potency, even if you make mistakes.
- Lots of Strong, Direct Light – Why? Light = food for
plants. More light is better (up to a point). Especially in flowering.
- The Right Nutrients at the Right Time – Why? Faster greener growth. But more importantly, proper nutrition in the flowering stage greatly increases bud quality, yields, and potency.
- Great Watering Habits – Why? Plants grow faster (and get fewer deficiencies) when given the right amount of water.
- Harvest at the Right
Time – Why? Choosing the right harvest time maximizes yields, potency, and effects.
Click here for 5 QUICK wins to boost your harvest! Speaking of #1, I love
these strains for home growers: Blue Dream (pictured), Candy Games #38, and Purple Ghost Candy.
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Quick question for you, grower… Nebula and Sirius here. Tell us your biggest grow struggle (temperature, deficiencies, slow seedlings...), and next week we'll show you how to fix it. Tell us your biggest grow challenge. Your answers help us choose which free guide to release first, as we prepare to launch the new 2026 version of our Home Grow Masterclass. Happy Growing, Nebula & Sirius P.S. Even one word helps! Once the #1 challenge is in, we'll release the free guide. Free Digital Tools on GrowWeedEasy.com Recommended Cannabis Seed Sources
These sources have gotten great reviews from our readers:
- Seed Supreme – Florida, United States
- ILGM (I Love Growing Marijuana) – California, United States
- North Atlantic Seed Co. – Maine, United States
- Seedsman – Ships from US & Europe
- MSNL – Netherlands bank with shipping centers in US, Canada &
UK.
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🌳 Check Out Our Grow Community!
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Check out our friendly growing community to ask questions, discuss your grow, share pictures, or otherwise talk about growing cannabis with other real growers! Ask Questions & Talk with Other Growers! Please note: We let each person in manually, so please be patient after you request to join. We'll let you in as soon as possible!
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Who Runs GrowWeedEasy.com?
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Nebula Haze: When I first started growing, I struggled. Now, it is my mission to make it easy for new growers to get started while helping advanced growers get bigger, better yields with less time and money. We update/add articles every week. Anyone and everyone can grow if they want to! Current Favorite Strain:
Mandarin Cookies (learn more in my article about relaxing limonene) Learn which seed sources are recommended by Nebula Haze Sirius Fourside: Sirius Fourside is a hobbyist grower who has gained the bulk of his experience growing in water as a medium (deep water culture, bubbleponics). Copyright (c) 2026 GrowWeedEasy.com NOTE: If links aren't working or if pictures are not showing up properly, please view the full newsletter here: http://archive.aweber.com/gwe-updates Disclaimer: Grow Weed Easy only recommends products that we've either personally checked out ourselves, or that come from people we know and trust. For doing so, we may receive a commission. Nothing in this e-mail should be considered personalized Financial, Legal, or Medical Advice. The contributors to this magazine grow legally under their local laws but are not lawyers or medical professionals. Any decision to grow
marijuana should only be made after consulting with an experienced lawyer or other legal adviser. Any medical decisions should only be made after speaking with a doctor. Be safe! How Did I Sign Up For This Newsletter? Our records indicate that requested to be added to the GrowWeedEasy.com weekly newsletter at . Date: January 22, 2026
To unsubscribe, click here: https://www.aweber.com/z/r/?ThisIsATestEmail
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