Join Tyler and Egan as they break down the science and strategy behind defoliation in commercial cultivation. Are you removing too much? Too little? Learn how to balance airflow, light penetration, and plant energy reserves for optimal yield.
Chapters 👇
00:00 – Why Overdefoliation Happens
00:41 – Leaves = Energy: What You Lose When You Strip
02:47 – Balancing Light Penetration vs. Storage
03:37 – How to Read Your Canopy Like a Pro
05:13 – What Causes Overgrowth and How to Prevent It
06:01 – The Light Trick to Set a Defol Standard
07:26 – Strain-Specific Defol: Not One-Size-Fits-All
08:28 – Why You Might Want to Remove Top Leaves Instead
08:50 – Don’t Forget the Middle Canopy!
Transcript:
Some people go too hard on early defoliation—plants end up nearly naked. Leaves are the surface that captures light; without them, there’s no photosynthesis. While heavy early stripping can sometimes finish fine, other times you’re left with a canopy that’s too thin: yes, light reaches the bottom, but overall canopy density drops below the optimal range. You might gain a little density down low, but what opportunities did you lose by removing so much leaf so early?
A better approach is cautious, staged work: you can always take more off, but you can’t put it back. Start conservatively, let the canopy fill in, then run a second, more selective pass. Focus on the inner canopy leaves that are stacked or resting on other leaves—those trap moisture, restrict airflow, and create microclimates where powdery mildew can thrive.
Every leaf is both photosynthetic area and a storage reservoir for assimilates (carbohydrates) the plant will need later. When you haul hundreds of pounds of leaf out of a room, you’ve removed hundreds of pounds of stored light energy the plant could have used in flower. The goal isn’t “no defoliation”; it’s smart, selective defoliation so you gain penetration without starving the plant.
Use visuals and simple checks. From directly above (a ladder photo helps), look “as the light” through the trellis squares: where are the gaps, how thick is the canopy, how uniform is it? Remove leaves strategically to let light hit most flower sites—but not so much that you see white benchtop shining through everywhere (that’s overdone). As a quick diagnostic, sit at bench level: at first you may see no light hitting the bench; as you prune, aim for a gentle, uniform trickle of light reaching the tabletop—use that as the standard for the rest of the table or zone, while adjusting for strain differences in leaf size and density.
Metering helps too. Drop a PPFD sensor through the canopy; if you’re near zero by 24–30 inches down, the canopy is too dense. You can mitigate with leafing, but it’s better to fix the upstream causes—veg length, spacing, and how the plant was guided through trellis—so you don’t end up doing massive, labor-heavy corrective stripping later.
Avoid rigid “percent removed” rules. Read the canopy. Establish a visual target (top-down fullness plus controlled bench-level penetration), then apply that standard consistently table by table, tier by tier, and cultivar by cultivar.
One counterintuitive tip: many people strip the lower and middle leaves and leave the tops packed with leaf because they’re newer and highly active. In practice, removing a bit more in the top ~12 inches and leaving a bit more in the lower half of the productive canopy often works better. The top leaves are the ones most likely to block light from reaching the majority of flower sites in the middle. The top sites will usually develop no matter what; the middle is where most of your potential yield lives. Open the top selectively to drive light into the middle, and keep some lower leaves to catch the photons that make it that far. That balance—trellis timing, plant spacing, branch spacing, canopy depth, and foliage density—is how you hit high grams per square foot without creating a labor and energy sink.
