Flowering typically runs 7-12 weeks depending on strain, and it follows a fairly predictable pattern. Knowing what “normal” looks like week to week helps you catch real problems early instead of panicking over normal plant behavior — and helps you time harvest correctly instead of guessing.

Weeks 1-2: The Stretch

Right after switching to a 12/12 light schedule (or as an autoflower naturally transitions), the plant enters a rapid growth spurt often called “the stretch.” Expect the plant to gain 50-100% of its current height during this period — this is normal and expected, not overgrowth to panic about.

What to watch for: the first signs of pre-flowers (small white hairs called pistils) appearing at node sites, confirming the plant has successfully switched to flowering.

What to do: this is your last real window for any training — after the stretch slows, the plant’s energy shifts fully to bud-site development.

Weeks 3-4: Bud Site Formation

Growth in height slows significantly. Small bud sites begin forming at each node where pistils appeared. Plants shift from “leafy and stretching” to visibly starting to bulk up at these sites.

Feeding note: this is when phosphorus and potassium needs really ramp up — see our feeding schedule guide for specific ratios during this window.

Weeks 5-6: Peak Bud Development

Buds noticeably thicken and the plant’s smell intensifies significantly as terpene production ramps up. This is usually the period of heaviest nutrient uptake — many growers see their fastest bud-weight gains during these weeks.

What to watch for: pistils that were previously white will start to darken (orange/amber/brown) on some buds, though this varies a lot by strain and isn’t itself a harvest signal yet.

Weeks 7-8: Bud Maturation

Buds become noticeably denser and heavier, and the plant’s leaf-to-bud ratio starts to shift as fan leaves begin naturally yellowing (a sign nitrogen is being pulled into the buds, which is normal at this stage — not a deficiency to correct).

What to do: for most photoperiod strains, this is a reasonable window to consider starting your final flush (switching to plain, pH-balanced water) depending on your strain’s total flowering time.

Weeks 9-12+ (Strain Dependent): Ripening and Harvest Window

This is where flowering time varies most by strain — some finish around week 8, sativa-dominant strains can run to week 11-12+. The most reliable way to judge harvest timing isn’t the calendar, it’s the trichomes.

Reading trichomes (requires a jeweler’s loupe or macro phone lens):

• Clear trichomes: not ready yet — still developing
• Milky/cloudy trichomes: peak THC window — most growers harvest somewhere in this range
• Amber trichomes: THC is starting to degrade into more sedative compounds — a higher amber ratio means a more relaxing, “couch-lock” effect, which some growers want and others don’t

Most growers aim to harvest when trichomes are roughly 70-90% milky with a small percentage of amber, adjusting toward more amber if a heavier, more sedating effect is the goal.

Quick Reference Timeline

Flowering time varies significantly by strain, which matters if you’re planning around a specific harvest window. Check the flowering time listed on each strain’s product page before you start your grow.