Trichomes are the tiny mushroom-shaped resin glands on cannabis flower and surrounding leaves. They produce essentially all the cannabinoids (THC, CBD, CBG, CBN, etc.) and terpenes that make cannabis cannabis. Three main types: bulbous (tiny, on leaves), capitate-sessile (medium, on flower), and capitate-stalked (largest, the iconic resin globe on a stalk).

Capitate-stalked trichomes are what growers watch for harvest timing. Under a jeweler's loupe or microscope:

Clear trichomes = cannabinoids still developing. Harvesting now yields lighter, more cerebral effects but less potency overall.

Milky/cloudy trichomes = peak THC. Most growers target 70-90% milky for the strongest effect.

Amber trichomes = THC degrading to CBN, more sedative, body-heavy effect. Some indica growers target 20-30% amber for a couch-lock profile.

Beyond color, watch the gland heads — they should be intact, not collapsed or browning. Trichome health degrades quickly after peak; over-mature flower loses both potency and terpene complexity.

Different cultivars peak at different windows. Sativa-leaning lines often want harvest at 50-70% milky for the cleaner head effect; indica-leaning lines tolerate more amber for the couch-lock end.

Do I really need a loupe?+
Yes if you want to dial in harvest timing. A 30-60x loupe or pocket microscope is under $20 and changes everything.
What's 'amber-rush'?+
Slang for harvesting too late and ending up with overly sedative, sometimes harsh flower. Amber percentage above ~40% is generally too far.