Weed flowering stages are the final and most exciting part of a cannabis plant’s life cycle, when buds form, swell and fill with resin. This week-by-week guide explains what usually happens from flower week 1 through harvest, how to read trichomes, and how growers decide when a plant is ready.
Quick Facts: Weed Flowering Stages
- Typical length: About 8 to 10 weeks for many hybrids. Some sativa-leaning strains take 10 to 12 weeks or longer.
- Trigger for photoperiod plants: Roughly 12 hours of uninterrupted darkness each day.
- Autoflowers: Begin flowering based on age, not light schedule.
- Key harvest signals: Pistil color and trichome color, used together.
- Where cannabinoids concentrate: In trichomes on the flowers and small sugar leaves.
What Triggers Cannabis Flowering Stages?
Most cannabis plants are photoperiod plants. They stay in vegetative growth while days are long. Then, once nights reach about 12 hours, they switch to flowering. Indoors, growers trigger this change by moving lights to a 12 hours on, 12 hours off schedule.
Autoflowering plants work differently. Thanks to ruderalis genetics, they start flowering on their own after a few weeks. To learn more about seed types, see our guide to cannabis seeds, feminized and autoflower.
A Quick Look at Flower Anatomy
- Cola: The main cluster of buds at the top of a branch.
- Calyx: The small teardrop-shaped structures that make up a bud.
- Pistils: Hair-like strands that start white and darken over time. They hold no meaningful cannabinoids.
- Trichomes: Tiny resin glands that hold most of the plant’s cannabinoids and terpenes.
- Sugar leaves: Small, resin-dusted leaves nestled within buds.
- Fan leaves: Large leaves that capture light and carry little resin.
Weed Flowering Stages Week by Week
Every strain moves at its own pace, so use this timeline as a general guide rather than a fixed schedule.
Flower Week 1: The Transition
In flower week 1, the plant shifts from vegetative growth toward flowering. Growth often speeds up during this period, which growers call “the stretch.” Some plants nearly double in height over the first few weeks.
Week 2: First Pistils Appear
Growth continues, but energy begins shifting from leaves and stems toward flower sites. Tiny white pistils start to appear where branches meet the main stem. This is also when male plants, if any, become easier to identify.
Week 3: The Stretch Slows
Vertical growth slows and eventually stops. Meanwhile, more pistils form, and the first small budlets start to take shape near the end of the week.
Week 4: Buds Take Shape
Budlets grow noticeably larger and begin to look like real flowers. Pistils remain mostly white, and the plant’s focus is now firmly on bud production.
Week 5: Bulking and Aroma
Buds keep fattening, and new ones form along the main colas. Trichomes become more visible, giving buds a frosty look. In addition, the plant’s aroma gets much stronger at this point.
Week 6 Flower: Ripening Begins
Week 6 flower is often when buds start to look close to finished. Pistils begin turning from white to orange, red or light brown. Under magnification, many trichomes shift from clear to cloudy.
Week 7: Maturing
Buds continue to swell and harden. More pistils darken and curl inward, and trichomes keep turning milky. Fan leaves may start to yellow as the plant draws on stored nutrients.
Week 8 and Beyond: Harvest Window
Many strains reach their harvest window around week 8 or 9. Sativa-leaning strains may need several more weeks. At this point, growers watch trichomes closely to choose the right moment.
Reading Trichomes and Pistils
Trichome color is the most reliable harvest indicator. A jeweler’s loupe or small digital microscope makes them easy to see.
- Clear: Not yet mature. Harvesting now is generally considered early.
- Cloudy or milky: Mature. Many growers aim to harvest when most trichomes look cloudy.
- Amber: Further along. Some growers wait for a portion of trichomes to turn amber, based on personal preference.
A common rule of thumb is to harvest when at least half the pistils have darkened and curled, and at least half the trichomes are cloudy. Using both signals together helps, since one can change before the other.
Tips for the Cannabis Flowering Stages
- Protect the dark period. Light leaks during “lights off” can stress photoperiod plants.
- Watch humidity. Dense buds are prone to mold, so many growers lower humidity in late flower.
- Support heavy branches. Stakes or trellis netting keep colas from snapping.
- Handle gently. Touching buds can knock off trichomes.
- Plan for drying and curing. Post-harvest care strongly shapes flavor and smoothness, so have a dark, well-ventilated drying space ready before harvest day.
In DC, Initiative 71 lets adults 21+ grow up to six plants at home, with no more than three mature at once. See our guide on DC cannabis law for details.
After Harvest: Drying and Curing
Harvest is not quite the finish line. Most growers hang branches or lay buds on racks to dry slowly over about one to two weeks. Then they trim and store the buds in airtight jars, opening them regularly at first to release moisture.
This curing period often lasts several weeks. Many growers say it smooths the smoke and brings out aroma, which is why patient curing is a hallmark of quality flower.
Weed Flowering Stages FAQ
How long do weed flowering stages last?
Many strains flower for about 8 to 10 weeks. Sativa-leaning strains can take 10 to 12 weeks or more, while autoflowers follow their own shorter timeline.
What happens in week 6 flower?
Buds continue to ripen, pistils start changing color, and trichomes begin turning cloudy. Many plants look close to finished at this stage.
How do I know when to harvest?
Check both pistils and trichomes. Many growers harvest when at least half the pistils have darkened and most trichomes look cloudy.
Prefer flower that is already grown and cured? Explore our cannabis flower collection or the full menu, and order for same-day delivery anywhere in DC, or text (202) 948-6152. Adults 21+ with valid ID only: start low, go slow, and never drive after consuming.
