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A guide to cannabis flower.
Flower is the dried, cured bud of the cannabis plant. It’s the most traditional way to buy cannabis, and the one where freshness, aroma and how you consume it matter most.
What flower is
Flower is the harvested bud of the female cannabis plant, dried and cured. Look closely and you’ll see a frost of tiny resin glands called trichomes. That’s where the plant makes its cannabinoids (THC, CBD) and its terpenes (aroma).
Before flower reaches a California shelf, it’s tested in a lab, including for moisture. Dried flower must meet a water-activity limit meant to keep microbes like mold in check.
Common sizes
| Name | Weight |
|---|---|
| Gram | 1 g |
| Eighth | 3.5 g (an eighth of an ounce) |
| Quarter | 7 g |
| Half | 14 g |
| Ounce | About 28 g |
California’s adult-use daily limit is 28.5 grams of non-concentrated cannabis. Labels show net weight in both grams and ounces.
Reading the numbers
Flower labels list Total THC as a percentage, which includes THCA, the form that turns into THC when heated. A university review for Washington State notes that flower around 20% THC or more has become common in legal markets. The state’s safe-use brochure suggests that new consumers consider flower under 20% THC.
Higher THC isn’t automatically better. Aroma, freshness and how you consume it all shape the experience. Terpenes appear on the label when lab-verified, and they’re often the best clue to a product’s character. See our terpene guide.
Smoking vs. vaporizing
- Smoking in a pipe, water pipe or joint: effects begin within minutes, peak in about 20–30 minutes, and usually taper off over two to three hours.
- Dry-herb vaporizers heat flower without burning it. In a controlled study, vaporized flower produced stronger effects than the same dose smoked. If you switch to a vaporizer, take fewer puffs at first.
The National Academies found that regular cannabis smoking is associated with more frequent chronic bronchitis episodes. California also lists cannabis smoke under Proposition 65 as known to cause cancer.
Keeping flower fresh
Terpenes fade first, and THC slowly breaks down into CBN when exposed to light, heat and air. In one study, whole, unground buds stored cool held up best.
- Keep flower in an airtight container, away from light and heat.
- Grind just before use rather than in advance.
- Check the packaged date when you buy.
More in our storage guide.
Sources
- Sommano SR et al. Molecules (2020). The cannabis terpenes (trichomes and terpene production)
- California Code of Regulations, Title 4, § 17403. Labeling of cannabis (net weight in metric and U.S. units)
- California Code of Regulations, Title 4, § 17407. Cannabinoid content labeling
- California Code of Regulations, Title 4, § 15724. Total THC and label tolerance
- California Code of Regulations, Title 4, § 15717. Moisture content and water activity testing
- California Code of Regulations, Title 4, § 15409. Daily purchase limits
- Spindle TR et al. JAMA Network Open (2018). Acute effects of smoked and vaporized cannabis in healthy adults who infrequently use cannabis: a crossover trial
- Barrus DG et al. RTI Press (2016). Tasty THC: promises and challenges of cannabis edibles (inhalation vs. ingestion time course)
- University of Washington and Washington State University workgroup (2020). Cannabis concentration and health risks
- California Department of Cannabis Control and California Department of Public Health. Safe-use brochure required by SB 540
- Meili L et al. Frontiers in Plant Science (2020). Metabolic profiling of cannabis secondary metabolites for evaluation of optimal postharvest storage conditions
- National Academies of Sciences, Engineering, and Medicine (2017). The health effects of cannabis and cannabinoids
- California Office of Environmental Health Hazard Assessment. Proposition 65: cannabis (marijuana) smoke
This guide is general education, not medical or legal advice. Talk to a doctor about your health, and check current California law.