Short answer

Cannabis is ready when three signs line up: pistils change color and curl in, trichomes shift from clear to cloudy, and calyxes swell at the bud sites. The window lasts about 7 to 10 days. Check plants every 2 days near the end. Cut too soon and THC stays low. Wait too long and THC breaks down into CBN, which gives a flat, sleepy effect.

Pistil and calyx signs

Pistils are the hairs on each calyx. In weeks 4 to 6 of flower they stand out, white and straight. As the plant finishes, they darken to orange, brown, or amber and curl back toward the pod.

Pistil color alone is a weak signal. A plant under heat stress or close light can throw new white pistils on top of ripe lower buds, a shape called foxtailing. Judge ripeness at the calyx, not the top fan leaves. Calyxes also fatten in the last 2 weeks. Bud weight comes from that swell.

Trichome signs

Trichomes hold most of the cannabinoids and terpenes. Use a 30x to 60x loupe, a phone macro lens, or a USB microscope. Read the calyxes, not the sugar leaves. Sugar leaves turn amber 1 to 2 weeks before the calyxes do, so a leaf check gives a false green light.

  • Clear: heads look glassy. THC is still building.
  • Cloudy or milky: peak THC. This is the standard indoor harvest point.
  • Amber: THC oxidizes into CBN. About 10 to 20 percent amber fits a heavier body effect. Past 30 percent amber, the smoke shifts toward sedation.

Heads droop and stalks bend at full ripeness. Use white light or daylight for the check. Purple LED output hides amber and clear heads.

Four more signs

  • Bud growth stops. Calyxes stack and the plant stops adding new sites.
  • Water use drops. A pot that drank every day now goes 2 to 3 days.
  • Fan leaves fade. The plant pulls mobile nutrients out of the lower leaves.
  • Smell peaks, then levels. Terpene output can fall after ripeness.

Timeline

Photoperiod plants run 8 to 11 weeks in flower at 12 hours light and 12 hours dark. Autoflowering plants run on their own clock and finish 70 to 90 days from seed. Outdoor plants finish on daylight hours; most US regions harvest between late September and early November at northern latitudes.

Convenience and the harvest call

Convenience now shapes part of the decision. Autoflowering seed removes the light-schedule work and shortens the season, which suits short summers, small tents, and rental space. The trade-off: autoflowering plants yield less than photoperiod plants in the same pot, and a slow start cannot be fixed because the flower clock starts without a signal.

Tools got cheaper. A 30x loupe runs $10 to $20. Clip-on phone macro lenses run $20 to $40. Home THC test kits run $100 to $300; lab tests run $50 to $150 per sample. Dry rooms hold 60°F and 60 percent relative humidity for 10 to 14 days, then jars cure for 2 to 4 weeks.

What convenience does not change: the plant sets the date. Gear reads the signs faster. It does not move the signs.

Common mistakes

  • Judging by sugar leaves, which amber first.
  • Harvesting on a calendar date. Two plants from one seed pack can finish 10 days apart.
  • Checking trichomes under grow lights with a purple spectrum.
  • Cutting at the first amber trichome, when the profile still shifts for days.
  • Rushing the cure. Chlorophyll needs 2 to 4 weeks in jars to break down.