The Complete Autoflower Grow Guide: From Seed to Harvest in 10 Weeks

Learn How To Grow Autoflower Cannabis

If you’re short on time or space, autoflower cannabis strains are your best friend. These fast-flowering, low-maintenance genetics don’t wait for light cycles — they just grow, bloom, and finish in as little as 9–10 weeks.

But growing autoflowers from seed to harvest requires precision, especially if you want quality over quantity. Let’s walk through each week of growth with practical, no-BS advice pulled from real grower experiences.

 Week 1: Germination & Seedling Stage

• What Happens: The seed cracks, roots tap down, and your first tiny leaves (cotyledons) appear.
• Light: 18–24 hours of gentle LED light.
• Humidity: 65–70%
• Tip: Avoid transplanting! Autoflowers hate stress — germinate directly in your final pot (3–5 gallons fabric pots are ideal).

"I used the paper towel method, but I dropped the sprout straight into my final pot to avoid shock. It shot up in two days." — user: GreenMachine (420magazine)

 Week 2: Early Vegetative Growth

• What Happens: First true leaves appear, root system expands rapidly.
• Light: 18–20 hours (LED, 200–300 PPFD)
• Nutrients: Start very light veg nutrients at ¼ strength.
• Tip: Use a spray bottle and water in a small ring around the plant to encourage root searching.

 Week 3–4: Vegetative Push & Pre-Flower

• What Happens: Growth explodes. You'll see 4–5 nodes and perhaps signs of pre-flower pistils forming.
• Light: Keep at 18–20 hours.
• Training: Only do Low Stress Training (LST).
• Tip: Avoid topping or defoliating too much. Every day of growth matters with autoflowers.

"My first grow I topped an auto at week 4 and it stunted hard. Lost like 30% yield. LST only for autos now." — user: stealthbudder420 (Reddit/r/microgrowery)

 Week 5–6: Flower Initiation

• What Happens: Buds begin to form at nodes. Pistils stretch and white hairs are everywhere.
• Nutrients: Switch to bloom nutes (higher P and K). Ease in slowly.
• Environment: Drop humidity to 50–55%. Increase airflow.

 Week 7–8: Bud Development

• What Happens: Buds swell. Trichomes (frosty crystals) begin to form.
• Smell: This is when terpenes kick in. Use a carbon filter if needed.
• Tip: Monitor for pests like spider mites or powdery mildew.

Pro Tip: Use a jeweler’s loupe or 60x microscope to monitor trichome development starting around week 8.

 Week 9–10: Ripening & Harvest

• What Happens: Pistils darken, trichomes go from clear → cloudy → amber.
• Flush: Begin flushing with plain pH-balanced water 10–14 days before harvest.
• Harvest Timing:
• Cloudy trichomes = highest THC
• Amber trichomes = more sedative effect (CBN)

"Chopped at 20% amber and it hits like a couchlock freight train. Next time I’ll cut a week earlier." — Grower: terpterror87 (GrowDiaries)

 Final Yield & Curing

• Yield Expectation: 1–5 oz per plant (strain and setup dependent)
• Drying: 7–10 days at 60°F and 55% RH
• Cure: Jar and burp for 3–4 weeks minimum for best flavor and smooth smoke.

 Takeaways

• Autoflowers don’t wait — plan every step ahead.
• LST only — avoid high stress training techniques.
• Control your environment for best terpene and yield results.
• Monitor trichomes closely to time your harvest properly.

 Recommended Gear for Autoflower Growers

• 3 Gallon Fabric Pots
• Full-Spectrum LED (100W–200W per plant)
• PH Meter & Digital Thermo-Hygrometer
• Low Odor Strains (e.g., Northern Lights Auto, Blueberry Auto)

Want to Make It Even Easier?

Some headshops and online retailers now offer autoflower starter kits — seeds, soil, pots, lights, and nutrients all in one. If you're a beginner, that’s a great way to skip the learning curve.

*These statements have not been evaluated by the United States Food and Drug Administration.