A cannabis SCROG (screen of green) setup uses a horizontal screen or net stretched 8 to 12 inches above the pot rim, with 2 to 4 inch mesh openings, mounted on a frame that sits level across the canopy. You install the screen, tuck growing tips under the mesh to spread growth sideways, and flip to flower once the screen is roughly 70 to 80 percent full. The result is a flat, even canopy that captures light across the whole grow area instead of a single tall cola.
What is a SCROG setup and how does it work?
SCROG training spreads one or a few plants across a horizontal plane, forcing side branches to grow outward instead of upward. Each tip that reaches the mesh gets tucked back under, which redistributes growth hormones and produces many evenly sized colas. A flat canopy uses your light footprint better than a tall untrained plant.
Cannabis Scrogging Setup Instructions
What screen height and mesh spacing should you use?
Start the mesh 8 to 12 inches above the base of the plant or the top of the pot. Closer than that and you cannot reach under the canopy to water, prune, or inspect. Wider than that and lower growth stretches and shades out before it reaches the screen.
- Mesh size: 2 inch squares for small plants and tight spaces, 3 to 4 inch squares for larger indoor grows.
- Material: Soft nylon trellis netting or coated wire. Sharp wire cuts stems as they swell.
- Frame: PVC, wood, or a tensioned net held by corner posts. The screen must stay rigid under weight.
- Coverage: Match the screen to the exact area your light covers evenly.
When do you install the screen and flip to flower?
Install the screen when plants are 8 to 12 inches tall, before branches become stiff and woody. Tuck tips every two to three days during vegetative growth, letting the canopy fill outward from the center. Flip to 12/12 lighting when the screen is about 70 to 80 percent full, since the stretch period in early flower fills the remainder.
How do you tuck branches without breaking them?
Guide each tip under the mesh and let it reorient upward on the next square, working from the center outward. Bend stems while they are still supple, and support a creased stem with tape if it kinks. Keep the canopy surface level and pull taller tips outward to the edges rather than letting them rise.
What else matters in a SCROG room?
Clear leaves and small shoots below the screen so air moves freely and energy goes to the top canopy. Keep light 12 to 18 inches from the canopy with LEDs, and run oscillating fans above and below the screen. Check the underside weekly for pests, since a dense flat canopy hides problems.
Does SCROG work for CBD and hemp cultivars?
Yes. CBD type III cultivars respond to the same canopy management, and SCROG helps keep a uniform height that simplifies harvest timing. Fill the screen slightly less with vigorous sativa-leaning genetics to leave room for the flower stretch.
What are the most common SCROG mistakes?
- Waiting until flowering to install the screen, when stems are too rigid to tuck.
- Filling 100 percent of the mesh before the flip, which causes crowding and light blockage.
- Using a screen wider than the light footprint, leaving outer squares in shade.
- Skipping under-canopy pruning, which traps humidity and invites mold.
Do you need more than one plant for SCROG?
No. A single plant in a larger pot can fill a 3 by 3 foot screen with enough vegetative time. Multiple plants fill the mesh faster but demand more consistent pruning to keep the canopy even.