Cannabis harvest time: quick answer
Harvest cannabis when trichomes on the buds are cloudy and most pistils have turned orange-brown. For CBD hemp, cloudy trichomes with few amber heads mark the target window. Weeks in flower give a range, not a fixed date.
Check trichomes at 30x to 60x
Trichomes are the resin heads on buds and small leaves. Use a 30x to 60x loupe or a microscope. Check buds, not fan leaves. Look at the top cola, a mid bud, and a lower bud. Light and heat differ by site, so trichomes mature at different rates.
Trichome color stages
- Clear: resin heads look glassy. Cannabinoid levels are low. Not ready.
- Cloudy or milky: heads look white. This is the common harvest window for high-THC cannabis and for CBD hemp.
- Amber: heads look brown or tea colored. THC breaks down to CBN. For CBD, amber heads signal oxidation and a past-peak plant.
Count heads in several spots. A 70% cloudy, 20% clear, 10% amber mix is one common target for high-THC flower. CBD hemp growers often cut with cloudy heads and less than 20% amber. Strain and lab test decide the final call.
Pistils and bud shape
Pistils are the hairs that push out of the calyx. They start white and stand up. As the plant nears harvest, most turn orange, brown, or red and curl inward. Buds swell, and calyxes look full. A few new white pistils can appear late. Do not judge by pistil color alone. Heat, light stress, and handling can brown pistils before peak.
Weeks in flower
Photoperiod cannabis flowers for about 8 to 11 weeks after the light flip. Autoflower cannabis runs about 8 to 10 weeks from seed, with a shorter flower phase. Breeder notes give a range. Start checking trichomes one week before the low end of that range.
- Week 1 to 3: stretch and flower start. Trichomes clear.
- Week 4 to 6: bud swell. Trichomes clear to cloudy.
- Week 7 to 10: cloudy to amber. Check every 2 to 3 days.
Weather, time of day, and mold
Cut in a dry window. Wait for dew to dry. Rain and high humidity raise bud rot risk. Check dense colas for gray mold, brown patches, and a musty smell. A plant past peak loses resin and gains mold risk. Harvest in the morning after dew, not during rain.
CBD hemp and the 0.3% THC limit
US hemp must test at or below 0.3% THC on a dry weight basis. Harvest timing shifts THC and CBD levels. Cut too late and THC can rise. Cut too soon and yield and CBD levels can fall. Send samples to a lab before harvest. Keep harvest records by field, strain, and date.
What to record
- Strain name and seed or clone source.
- Light flip date or seed date.
- Trichome ratio at each check.
- Pistil color and bud density.
- Scent, mold signs, and weather.
Repeat checks on the same buds. A loupe and a notebook do more than a calendar.