20 FASTEST Flowering Strains to Grow from Seed

Both autoflowering seeds and photoperiod strains. The fastest flowering cannabis strains to grow from seed to harvest. Ordered by quickest start to finish grow time.

Fastest Flowering Autoflower Strains

Sour Crack Auto

THE FASTEST autoflowering strain that Mephisto Genetics has ever grown, Sour Crack Auto finishes in only 7 weeks from seed (germination). Sour Crack Auto is made from Green Crack Auto and 24 Carat genetics. The short plants stay 20 to 28 inches tall, forming rock-hard, resinous buds in quick time. A great strain for commercial quality Sea of Green autoflower grows. High potency nuggets tested near 20% THC.

Flowering Time	7 weeks
Strain Breeder	Mephisto Genetics
Pack Size	1/3/7/18 seeds
Yield	Indoors: 30–60 g/plant Outdoors: 60+ g/plant

+ Speed Auto

+ Speed Auto by Sweet Seeds are among the quickest finishing autoflower seeds to grow, being ready to harvest at just 7 weeks from germination. This strain is comprised of the breeder’s own Critical Mass and Speed Devil #2 Auto genetics, bred for yield and deep aromatic properties. + Speed Auto does well both indoors and outdoors. The plants grow 20 to 35 inches in height, producing harvests up to 150 grams each. Tastes sweet, fruity, and cheesy.

Flowering Time	7 weeks
Strain Breeder	Sweet Seeds
Pack Size	3/5/10/25/100 seeds
Yield	Indoors: 350–500 g/m2 Outdoors: 30–150 g/plant

Fast Bud #2 Auto

Fast Bud #2 improves upon Sweet Seeds’ Fast Bud line, a member of the Diesel family of cannabis. This award-winning sativa dominant autoflower strain is quick to mature at 7 to 8 weeks from seed. Only reaching 20 to 35 inches in height, the short plants are multi-branched and form a large number of bud sites, making it an easy strain to grow with very productive yields. Fast Bud #2 Auto has a sweet aroma, exotic taste, strong head high, and powerful body stone. 15–20% THC.

Flowering Time	7–8 weeks
Strain Breeder	Sweet Seeds
Pack Size	3/5/10 seeds
Yield	Indoors: 350–500 g/m2 Outdoors: 20–70 g/plant

Sweet Skunk Auto

Sweet Skunk Auto is one of Sweet Seeds’ best-yielding and most resinous autoflower weed strains. Genetically, it’s a hybrid of Early Skunk and Critical Mass, backcrossed twice to Early Skunk. The plants grow rapidly and get 24 to 35 inches tall, finished at just 7½ weeks from germination. Its buds are dense and covered in trichomes. Intense skunk aromas with a sweet and spicy background. Physically relaxing with an uplifting head high. 16–20% THC.

Flowering Time	7½ weeks
Strain Breeder	Sweet Seeds
Pack Size	3/5/10/25/100 seeds
Yield	Indoors: 400–550 g/m2 Outdoors: 35–150 g/plant

Alaskan Purple Auto

Alaskan Purple Auto by Seedsman, one of the best seed banks, is a 90% indica purple weed strain that produces good yields in a short time. It finishes growing at 8 weeks from seed, with some phenotypes ready to harvest at week 7. They are easy growing, sizable plants for an autoflowering strain that mature one week later when grown outdoors. Ripe, fruity sweet flavors, and 15–20% THC content.

Flowering Time	7–8 weeks
Strain Breeder	Seedsman
Pack Size	1/3/5/10/100 seeds
Yield	Indoors: 400–550 g/m2 Outdoors: 40–200 g/plant

Crystal Candy XL Auto

Crystal Candy XL Auto is a large autoflowering marijuana strain bred from tall phenotypes of Sweet Seeds’ Crystal Candy Auto line. This mostly sativa variety is suitable for both indoor and outdoor growing. The plants reach a height of 35 to 55 inches, ready for harvest only 8 weeks from seed. Its buds are packed with trichomes and have a very fruity scent. 14–19% THC.

Flowering Time	8 weeks
Strain Breeder	Sweet Seeds
Pack Size	3/5 seeds
Yield	Indoors: 425–650 g/m2 Outdoors: 60–300 g/plant

Sweet Gelato Auto

Sweet Gelato Auto by Sweet Seeds is an autoflowering version of one of the most prestigious cannabis strains from the Bay Area—Gelato (Sunset Sherbet x Girl Scout Cookies “Thin Mint”)—crossed to Killer Kush Auto. The resulting plants offer generous yields in just 56 days from germination. Its dense buds are covered in large trichomes. The scent is earthy, sweet, and fruity with hints of mint and citrus. 18–23% THC.

Flowering Time	56 days
Strain Breeder	Sweet Seeds
Pack Size	3/5 seeds
Yield	Indoors: 375–500 g/m2 Outdoors: 50–175 g/plant

Sweet Cheese XL Auto

Sweet Cheese XL Auto is a fast and furious Cheese strain that offers greater size, yield, and resin production than Sweet Seeds’ original Sweet Cheese Auto. This mostly sativa strain autoflower is ready to harvest at 8 weeks from seed, growing to a height of 30 to 55 inches. It has an intense, remarkably sweet, skunky scent and powerful yet relaxing high. 15–20% THC.

Flowering Time	56 days
Strain Breeder	Sweet Seeds
Pack Size	3/5/25/100 seeds
Yield	Indoors: 375–600 g/m2 Outdoors: 45–190 g/plant

Purple Punch Auto

Purple Punch Auto is a fast, productive, and flavorful autoflower variety sold by Barney’s Farm Seeds. A top performer indoors and out, this low-maintenance, mostly indica strain shows resistance to mold, mildew, mites, and cold weather. The plants max out at 31 inches tall over their short lifecycle that takes between 50 to 60 days from seed. Its colorful, dense buds are rich in resin and terpenes with scents of sweet apple pie and cloves. Up to 18% THC.

Flowering Time	50–60 days
Strain Breeder	Barney’s Farm Seeds
Pack Size	1/3/5/10 seeds
Yield	Indoors: 350 g/m2 Outdoors: 400 g/plant

Chocolate Skunk Auto

A “60-day wonder” strain being ready to cut 60 days from seed germination, Chocolate Skunk Auto by 00 Seeds is an autoflowering hybrid of Chocolate Skunk and ruderalis genetics. The plants grow large for an auto strain at over 40 inches tall. Chocolate Skunk Auto produces beautiful compact, crystal-covered buds that smell great. 17% THC.

Flowering Time	60 days
Strain Breeder	00 Seeds
Pack Size	3/5 seeds
Yield	Indoors: 250–350 g/m2

Fastest Flowering Photoperiod Strains

Gigabud

Gigabud is a Big Bud and Northern Lights hybrid that finishes flowering in a speedy 5 to 6 weeks. These thirsty, medium-sized plants grow vigorously in veg and flower, producing massive quantities of resinous, fruity buds. There is also an autoflowering Gigabud strain for sale.

Flowering Time	5–6 weeks
Strain Breeder	G13 Labs
Pack Size	5 seeds
Yield	450+ g/m2

Hash Plant

The famous Sensi Seeds Hash Plant indica originates from Afghani genetics bred in the Northwest United States that was brought to Sensi Seeds in Holland, where it was crossed to another Afghan variety—Northern Lights. Ready to harvest in as quick as 40 days from flowering, Hash Plant seeds grow fast, in a stout, thick manner. The buds are super dense, very sticky, and ideal for making hash. A good choice for breeders.

Flowering Time	40–45 days
Strain Breeder	Sensi Seeds
Pack Size	10 seeds
Yield	400–500 g/m2

Green Poison Fast

Green Poison Fast by Sweet Seeds is a top-quality weed strain that forms super frosty and tight buds. This unique feminized seed strain was made by breeding out the ruderalis gene present in the original autoflowering Green Poison to create a remarkable, high-yielding photoperiod variety. 70% indica genetics are responsible for its fruity, heavy, and dank marijuana buds.

Flowering Time	6 weeks
Strain Breeder	Sweet Seeds
Pack Size	3/5/10/25/100 seeds
Yield	Indoors: 500–600 g/m2 Outdoors: 500–700 g/plant

Passion #1

Passion #1 is an outdoor indica strain from the seventies in California that made its way over to Holland during the eighties. This stable, easy-to-grow regular seed strain gets huge both outdoors and indoors, finishing its flowering cycle in a mere 6 weeks of bloom time. Passion #1’s citrus-like buds are long, dense, and full of resin. 18.6% THC content.

Flowering Time	6 weeks
Strain Breeder	Dutch Passion
Pack Size	10 seeds
Yield	250–750 g/plant

Tropicanna Poison F1 Fast

Tropicanna Poison F1 Fast by Sweet Seeds is an excellent fast flowering strain bred for speed and potency. It was created using an elite Tropicanna Cookies clone crossed to a red flower phenotype and Red Poison Auto. Roughly 80% of the resulting plants get red bud coloring. This very productive variety is finished at only 6 to 7 weeks of bloom. The buds are dense, extremely resinous, and have intensely sweet scents and flavors. 16–24% THC.

Flowering Time	42–49 days
Strain Breeder	Sweet Seeds
Pack Size	3/5 seeds
Yield	Indoors: 450–600 g/m2 Outdoors: 400–650 g/plant

Big Nugs Fast

As the name suggests, Big Nugs Fast grows big nugs—fast. It’s a photoperiod hybrid that’s ready to harvest in only 6 to 7 weeks flowering time. This high yield weed strain is bred from Big Bud / Critical Mass (Afghani x Skunk) crossed to Seedsman’s fast-finishing male. Similar to Big Bud, Big Nugs Fast grows thick heavy buds, which may need to be propped up during flowering. Yields are high—expect dense, pine cone-shaped buds with fruity, hashy qualities.

Flowering Time	6–7 weeks
Strain Breeder	Seedsman
Pack Size	1/3/5/10/100 seeds
Yield	450–550 g/m2

C99 x Blueberry Fast

C99 x Blueberry Fast is a rapid flowering, mostly sativa weed strain that’s ready to harvest in just 45 days from the start of bloom cycle. The infamous C99 strain is crossed to Blueberry and then bred with Seedsman’s fast parent, resulting in sativa dominant seeds that finish quickly. Its Thai genetics present help C99 x Blueberry Fast grow big during flowering, so expect some stretching. High yields of thick, potent marijuana buds.

Flowering Time	6–7 weeks
Strain Breeder	Seedsman
Pack Size	1/3/5/10/100 seeds
Yield	350–450 g/m2

Gorilla Girl F1 Fast

Gorilla Girl F1 Fast by Sweet Seeds is an extra-fast version of Gorilla Girl featuring extreme potency and production. The sativa dominant plants are ready to harvest after just 7 weeks of flowering. Its buds are known for their high resin content, with calyxes completely covered in frosty trichomes. The aroma and taste are sweet and fruity with earthy, woody notes. Strong effects—up to 24% THC.

Flowering Time	49 days
Strain Breeder	Sweet Seeds
Pack Size	3/5 seeds
Yield	Indoors: 400–500 g/m2 Outdoors: 350–600 g/plant

Pineapple Express #2

Pineapple Express #2 is a faster flowering, higher-yielding version of G13 Lab’s original Pineapple Express. A favorite weed strain among growers in humid climates, Pineapple Express #2 grows huge outdoors and has high resistance to mold and moisture. Its buds are large, fruity, and full of trichomes.

Flowering Time	45–50 days
Strain Breeder	G13 Labs
Pack Size	5 seeds
Yield	Indoors: 700 g/m2 Outdoors: 900–1300 g/m2

Pakistan Valley

Originating from the Hindu Kush mountains, Pakistan Valley by WOS is a landrace pure indica cannabis strain that grows quickly, finishing its flowering phase in just 45 to 55 days. It is a compact, vigorous grower, especially suited towards dry climates where its buds bulk up dense and resinous. Super sticky and potent—over 20% THC. For sale as both regular and feminized seeds.

Flowering Time	45–55 days
Strain Breeder	World of Seeds
Pack Size	10 seeds
Yield	Indoors: 400 g/m2 Outdoors: 700 g/m2

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