Jack 47 Auto by Sweet Seeds – High-THC Autoflowering Strain for Fast, Potent Harvests

Jack 47 Auto by Sweet Seeds is a lightning-fast, high-THC autoflowering strain that delivers premium sativa power in just 9 weeks from seed to harvest, perfect for growers who want big effects and bold flavors without the wait.

Overwhelmed by complicated grows and weak yields?

Starting your first autoflowering grow can feel like stepping into a jungle with no map. You’ve got seeds, soil, lights — but no clear order, no rhythm. You wonder: when to water? When to feed? How much space does it need? Without a solid plan, it’s easy to mess up timing, overstimulate the plant, or end up with airy buds and a lackluster high.

And when the results are disappointing, you start questioning the seed — when the real issue was the process. Missed windows, poor structure, or stress during flowering can make even the best genetics underperform. It’s frustrating, especially when you’re chasing that legendary Jack Herer energy.

Jack 47 Auto isn’t just another fast strain — it’s a complete phase-based system in seed form. With the right steps, this sativa-dominant powerhouse grows predictably, fills your space with citrus-terpene magic, and rewards you with dense, frosty buds that hit hard and clear. Follow the flow, and you’ll harvest like a pro — even if it’s your first time.

Phase 1: Preparing the Ground

Before you even crack the seed, set the stage for success. Jack 47 Auto thrives when its environment is stable from day one. This strain doesn’t forgive wild swings — but it rewards consistency with explosive growth and resin production.

• Choose a location with stable temps: 22–26 °C (71.6–78.8 °F)
• Ensure 60–70% humidity for seedlings
• Use well-aerated soil or coco with good drainage
• Prepare pots of 18–27 L (4.76–7.13 gal) for autoflowering
• Test pH: aim for 6.0–6.5 in soil, 5.8–6.2 in coco

Phase 2: Setting Up the Plant

Germination is where the journey begins — and doing it right prevents early stress that can haunt the plant later. Jack 47 Auto doesn’t like being moved twice, so start in its final pot whenever possible.

1. Germinate seeds between damp paper towels at 24 °C (75.2 °F)
2. Plant when the taproot is 0.5–1 cm (0.2–0.4 in) long
3. Place seed 1–1.5 cm (0.4–0.6 in) deep, root down
4. Water lightly with pH-balanced water
5. Provide 18–20 hours of light daily from day one

Phase 3: Grow Step by Step

1. Keep lights 40–60 cm (15.75–23.62 in) above canopy
2. Water when topsoil feels dry — avoid overwatering
3. Begin mild nutrients in week 2–3, increase gradually
4. Use Low Stress Training (LST) to spread the canopy
5. Watch for pre-flowers around week 3–4 — no pruning!
6. Switch to bloom nutrients at week 4–5
7. Support heavy colas with soft ties in late flowering

Phase 4: Closing, Maintenance & Learnings

After harvest, clean your space thoroughly to prevent pests and mold. Jack 47 Auto leaves behind sticky residue, so wipe down walls, filters, and trays. Save a few seeds from your best bud if you’re into breeding — but remember, this is an autoflower, so stability varies.

Take notes: flowering time, yield, flavor intensity, and any stress signs. Did it stretch more than expected? Was the smell stronger indoors? These details help you refine your next grow. For faster recovery, consider using Pure Zym by Plagron to break down root leftovers and prep the medium.

Advantages of Following This Flow Instead of Improvising

• Consistent 9-week harvests, every time
• Fewer mistakes in feeding and training
• Maximum resin and THC development
• Better airflow and mold resistance
• Higher yields up to 600 g/m² (1.76 oz/ft²)
• Clear, energizing effects without anxiety
• Rich citrus-incense flavor in every puff

Technical specifications

• Breeder / Brand: Sweet Seeds
• Type: Autoflowering
• Dominance: Sativa (76.9%) / Indica (20%) / Ruderalis (3.1%)
• Genetics: Jack Herer Auto × AK-47 (elite clone)
• Life cycle: 9 weeks from germination to harvest
• Indoor yield: 450–600 g/m² (1.33–1.76 oz/ft²)
• Outdoor yield: 50–200 g/plant (1.76–7.05 oz/plant)
• Indoor height: 50–120 cm (19.69–47.24 in)
• Outdoor height: 50–120 cm (19.69–47.24 in)
• THC: 18–21%
• CBD: 1.1%
• Difficulty: Low to medium
• Structure: Branching, compact colas, moderate stretch
• Climate: Temperate, Mediterranean, continental
• Resistance: Moderate to mold and pests
• Training: LST recommended, no topping or FIM
• Aromatic profile: Limonene, pinene, caryophyllene
• Flavour: Citrus, lemon, incense, sweet, fresh
• Effect: Creative, energizing, psychoactive — ideal for daytime use

Frequently Asked Questions

How long does Jack 47 Auto take to grow?

From seed to harvest, Jack 47 Auto takes approximately 9 weeks. It doesn’t require a change in light cycle, making it perfect for continuous indoor grows or quick outdoor harvests.

Is Jack 47 Auto good for beginners?

Yes. It’s forgiving, fast, and doesn’t demand advanced techniques. Just keep the environment stable, avoid overfeeding, and don’t prune — and you’ll get great results.

What does Jack 47 Auto smell like when growing?

During flowering, it emits a strong citrus-lemon scent with earthy incense notes. The aroma intensifies in late bloom — consider using a carbon filter if discretion is needed.

Can I grow Jack 47 Auto outdoors in winter?

Not recommended. While autoflowers are resilient, Jack 47 Auto performs best in warm, sunny conditions. Aim for spring or summer planting in the Northern Hemisphere.

Personal Experience of Pevgrow’s CEO (Alan)

I first grew Jack 47 Auto during a back-to-back indoor cycle, and it blew me away. I used a 20L Air Pot with living soil, 18/6 light, and minimal feeding — just enough to keep it green. By week 4, it was already showing fat pre-flowers, and the smell? Pure lemon Zest with a hint of temple incense. I didn’t touch it with LST, but I did tie down the main stem to even the canopy.

Harvest came at day 63 — dense, rock-hard buds covered in trichomes. After curing for three weeks, the high was clean, uplifting, and lasted for hours. No couch-lock, no paranoia — just pure creative flow. I’ve since recommended it to dozens of first-time growers, and every single one got a harvest they were proud of. If you want sativa power without the 12-week wait, this is your strain.