Cannabis Yield per Plant: Photoperiod Grow Guide

Cannabis Yield per Plant in a Photoperiod Grow

Most indoor photoperiod plants finish between 3 and 8 ounces (85 to 225 grams) of dried flower. A tuned room with strong light, a trained canopy, and a 6 to 8 week vegetative phase pushes single plants past 8 ounces. Plants in large pots or raised beds can clear 1 pound (454 grams). Outdoor photoperiod plants in full sun and a long season land between 1 and 2 pounds. The final number follows light delivered, canopy area, genetics, and how steady you keep the environment.

cannabis yield per plant photoperiod

What Sets the Final Number

• Light: Daily light integral is the single biggest lever. A flowering room running 600 to 1,000 PPFD at the canopy produces more flower weight than the same genetics under 400 PPFD.
• Canopy area: Buds grow on the canopy, not the stem. One plant scrogged into a 4 by 4 ft screen beats four untrained plants crammed in the same space.
• Genetics: Yields are strain specific. Check breeder notes and grower reports before you buy.
• Root zone: Pot size caps plant size. A 3 gallon pot limits a photoperiod plant; a 7 to 10 gallon pot does not.
• Environment: Vapor pressure deficit, temperature, and root-zone oxygen decide whether the plant turns light into flower weight or stress.

Prerequisites

• Feminized photoperiod seeds or clones with known yield data
• Space for a 2 by 2 ft to 4 by 4 ft canopy per plant
• Flowering-rated LED or HID, plus a PAR meter or phone PPFD app
• Thermometer, hygrometer, pH meter, and EC meter
• 6 to 8 weeks of veg time before the flip

Steps to Raise Yield per Plant

1. Pick a cultivar with documented indoor yields above 500 grams per square meter.
2. Fill 7 to 10 gallon fabric pots with a porous mix that drains in under three seconds.
3. Run veg at 18/6 and top the plant above the fifth node.
4. Train branches outward with low-stress ties until the canopy covers 80 percent of the screen.
5. Set flowering light to 12/12 with zero light leaks during the dark period.
6. Measure PPFD at the canopy and raise the fixture until readings sit near 800 PPFD.
7. Hold day temperature at 78 to 82 F and night temperature at 68 to 72 F.
8. Keep VPD between 1.0 and 1.5 kPa through weeks 1 to 6 of flower.
9. Feed a bloom schedule that holds runoff EC within 0.3 of the input EC.
10. Defoliate lower and inner leaves on day 21 and again on day 42 of flower.
11. Harvest when trichomes on calyxes read mostly cloudy with 10 to 20 percent amber.

Reading the Result

Dry weight is the only number that counts. Weigh flower after a 10 to 14 day dry at 60 F and 60 percent humidity, then again after two weeks of cure. A plant that fills a 3 by 3 ft canopy with dense tops commonly returns 6 to 10 ounces. Sparse, larfy plants from the same room return half that, which points to a light or canopy problem rather than bad genetics.

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Common Yield Killers

• Light leaks during the dark cycle, which trigger revegetation and loose buds
• Heat above 85 F in late flower, which stalls flower swelling
• Salt buildup in the medium that drives pH out of the 5.8 to 6.2 range
• Harvesting early, before calyxes finish swelling