Top 10 Fastest Autoflower Strains for Quick Harvests
Finding the fastest autoflower strains is every grower’s dream. Whether you’re just starting out or already have some experience, these rapid growers mean less waiting and more harvesting. This guide explains why autoflowers are so quick and highlights the top 10 fastest autoflowering strains to try.
What Makes Autoflower Strains So Fast?
Unlike photoperiod cannabis, which depends on changes in light cycles to trigger flowering, autoflowering strains bloom automatically with age. Their secret lies in Cannabis ruderalis, a hardy subspecies that evolved in cold, short-summer regions of Central and Eastern Europe. By crossing Ruderalis with Indica or Sativa genetics, breeders created plants that:
- Transition to flowering automatically
- Stay compact, often under 1 m tall
- Finish in just 7–10 weeks from seed to harvest
Some of the fastest growing autoflower strains can be harvested in only 42 days, making them the go-to choice for anyone seeking speed without compromising on flavour or potency.
The 10 Fastest Autoflower Strains
When speed is your priority, choosing the fastest autoflower strains can make all the difference. Below is a selection of 10 standout cultivars that deliver rapid results without sacrificing flavour, potency, or yield, making them ideal for both first-time growers and seasoned cultivators.
Big Bang Auto (Green House Seeds)
- Autoflowering
- Cosmic harmony and pain control
- 900 g/m² indoors
45 g/plant outdoors
One of the quickest autoflowers ever, finishing in just 42 days. This Indica-dominant strain delivers sweet, fruity buds with subtle floral undertones and 15–20% THC. The relaxing body effects make it a great evening smoke, while some growers also use it for stress and appetite issues. With yields up to 900 g/m² indoors, it combines speed with productivity.
Head Stash Auto (Big Head Seeds)
- Autoflowering
- A mind altering treasure
- 450 g/m² indoors
60 g/plant outdoors
Head Stash Auto is a balanced hybrid that matures in only 42–49 days. It brings together earthy, pine, and citrus notes for a refreshing flavour profile. With around 15% THC, the high is uplifting and sociable, paired with a pleasant body relaxation. Indoors, growers can harvest up to 450 g/m², while outdoor plants remain compact but rewarding.
+ Speed Auto (Sweet Seeds)
- Autoflowering
- The real thing!
- 350 - 500 g/m² indoors
30 - 150 g/plant outdoors
True to its name, + Speed Auto goes from seed to harvest in just 49 days. The flavour is sweet and fruity, with a mild cheesy edge that sets it apart. With THC levels of up to 20%, it offers a cheerful, creativity-boosting high that’s perfect for daytime use. Yields of 350–500 g/m² indoors make it a quick and reliable option.
Purple Punch Auto (Barney’s Farm)
- Autoflowering
- Devastating delight
- 350 - 400 g/m² indoors
400 g/plant outdoors
This 80% Indica hybrid finishes in about 50–60 days and produces dense, resinous buds. The flavour is reminiscent of apple pie with cinnamon and cloves, making it a favourite among flavour chasers. At 18% THC, the effects are a mix of euphoria and body relaxation, ideal for unwinding after work. Outdoors, expect up to 400 g per plant.
Sweet Skunk Auto (Sweet Seeds)
- Autoflowering
- 400 - 500 g/m² indoors
35 - 150 g/plant outdoors - Relief from the torment of the day
Ready in just 53 days, this hybrid is one of the most reliable fast autos. Its aroma is dominated by strong Skunk with citrusy undertones, while the flavour balances sweet and spicy notes. With around 20% THC, the high is both uplifting and soothing, offering the best of both worlds. Yields reach up to 500 g/m² indoors or 150 g outdoors.
2 Fast & 2 Vast Auto (Heavyweight Seeds)
- Autoflowering
- For giggling and for thinking
- 600 - 800 g/m² indoors
75 - 200 g/plant outdoors
Finishing in 56 days, this Indica-dominant strain lives up to its name. Sweet and fruity flavours accompany a powerful high that’s relaxing yet sociable, making it ideal for chilled gatherings. THC levels reach 20%, providing strong effects without being overwhelming. Indoors, growers can achieve impressive harvests of 600–800 g/m².
Doctor Jamaica Auto (Vision Seeds)
- Autoflowering
- A relaxed state of mind
- 250 - 450 g/m² indoors
This Indica-heavy strain is ready for harvest in just 56 days. Its tropical sweetness carries a classic Jamaican vibe, while the 19% THC ensures a potent, euphoric high that often ends in deep relaxation. Compact plants make it suitable for smaller grow spaces. Indoors, yields can reach up to 450 g/m² with minimal effort.
Scarlet Skunk Autoflower (Easy Grow Seeds)
- Autoflowering
- Colorful relaxation
- 450 - 500 g/m² indoors
250 - 300 g/plant outdoors
Finishing in just 42–49 days, Scarlet Skunk Autoflower is one of the fastest autoflowering strains with impressive yields. Indoors, it can produce 450–500 g/m², while outdoor plants give 250–300 g each under good conditions. With THC lfevels of up to 27%, its effects begin with a euphoric rush and sociable energy, before settling into calm relaxation and sleepiness. Classic skunky, sweet-and-sour flavours with cheesy undertones make this strain a favourite for fans of old-school cannabis profiles.
Black Herer Autoflower (Herbies Seeds)
- Autoflowering
- Relaxing yet functional
- 450 - 550 g/m² indoors
150 - 250 g/plant outdoors
This Sativa-dominant hybrid was bred for speed, completing its entire cycle in just 42–49 days, making it one of the fastest autoflower strains on the market. With THC levels up to 24% and a touch of CBD, it delivers an uplifting, motivating high that works equally well for daytime focus or evening relaxation. The flavour blends mellow sweetness with notes of frankincense, pine, and flowers, offering a refined smoke for connoisseurs. Indoors, yields reach 450–550 g/m², while outdoor plants can produce 150–250 g each, combining speed, potency, and generous harvests in one reliable package.
Crystal WW Autoflower (Herbies Seeds)
- Autoflowering
- Blissfully calming
- 500 - 600 g/m² indoors
100 - 150 g/plant outdoors
Crystal WW Autoflower is an Indica-dominant strain designed for growers in cooler climates with short summers, finishing its cycle in just 42–49 days. With legendary genetics including White Widow and C. Meth, plus a touch of Ruderalis, it combines strength, resilience, and speed. THC levels reach up to 26%, delivering a deeply relaxing body buzz paired with mental happiness, making it best for evening use. Indoors, yields can reach 500–600 g/m², while outdoor plants produce 100–150 g each, with buds that sparkle in resin and carry a pungent Skunky aroma blended with herbal and citrus undertones.
Why Choose and Where to Find the Fastest Autoflower Strains
Fast autoflowers are ideal for new growers thanks to their simplicity, small size, and resilience. For experienced cultivators, their quick turnaround means several harvests in a single season, proving that speed doesn’t mean sacrificing potency or flavour. If you’re ready to try the fastest autoflowering strains, Herbies offers a wide selection from trusted breeders. Here you can safely buy cannabis seeds with a germination guarantee, plus enjoy expert support and free seeds with every order. Quick, reliable, and rewarding — the fastest autos make growing easier than ever.
Herbies Head Shop expressly refuses to support the use, production, or supply of illegal substances. For more details read our Legal Disclaimer.
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