Short answer
Trichomes start clear and glassy. They turn cloudy white. They finish amber. Each stage runs about 7 to 14 days. Clear heads hold acidic cannabinoids. Cloudy heads hold peak THC. Amber heads hold more CBN.
What a trichome looks like
A trichome is a glandular hair on the cannabis flower. The head holds resin. The stalk holds the head above the plant surface. A mature capitate-stalked trichome looks like a mushroom: a ball on a short stem. The ball measures 50 to 100 micrometers across. You need 30x to 100x magnification to read the color of one head.
Cannabis grows three glandular types: bulbous, capitate sessile, and capitate stalked. Bulbous and sessile heads sit flat on plant tissue. Capitate-stalked heads carry the bulk of the resin and the color shift growers track.
cannabis trichomes turning milky early
Stage 1: clear
Look
The head is translucent. Light passes through the resin. The surface reflects a pin point of light. No white, no milk, no amber. The stalk is thin and holds the head upright.
Timing
Weeks 3 to 5 of the flower cycle. Heads form on calyxes first, then on sugar leaves.
Stage 2: cloudy
Look
The head turns opaque white, like watered milk. The resin stops passing light. The shape stays a ball on a stalk. Heads turn cloudy 2 to 3 days apart from each other.
Timing
Weeks 6 to 8 on a 9 week plant. This window holds the highest THC level for most cultivars.
Stage 3: amber
Look
The head shifts to amber, gold, or light brown. The color sits inside the resin, not on the plant tissue. Heads can wrinkle and stalks can bend as resin dries.
Timing
The final 1 to 3 weeks. THC degrades to CBN as the head oxidizes.
Mixed stages on one plant
Heads ripen at different rates. Top colas see more light and heat, so they turn amber first. Lower buds stay clear or cloudy 3 to 7 days longer. Check three points: top cola, middle canopy, lower branch.
How to check
- Use a 30x jeweler loupe for cloudy versus amber. Use 60x to 100x for clear versus cloudy.
- Point a white LED at the bud. Flash washes out the color.
- Look at the calyx, not the sugar leaf. Sugar leaves ripen 5 to 10 days ahead of the calyx.
- Sample 3 buds from different heights.
- Check once a day after week 6.
Harvest windows
- All clear: low THC, low CBN, harsh smoke.
- 70 percent cloudy, 30 percent clear: THC is rising.
- All cloudy: peak THC for most cultivars.
- 20 to 30 percent amber: THC still high, CBN rising, heavier effect.
- 50 percent amber or more: THC drops, CBN climbs, sedative profile.
Common mistakes
- Judging by pistils. Pistils turn orange 1 to 3 weeks before heads finish.
- Checking sugar leaves and calling the plant done.
- Counting heads under 20x. Color reads white on everything at that power.
- Waiting for every head to match. Heads never match.