Ultra-fast autoflower seeds and photoperiod strains list. The fastest flowering cannabis strains to grow from seed to harvest. Ordered by quickest start to finish grow time. Swift domestic US shipping.
Need to grow weed as fast as possible? The following speedy marijuana strains are super quick to grow and mature. For sale as cannabis seeds in autoflower (automatically flowers) or photoperiod (flowers according to light cycle).
You can purchase these fast-growing weed seeds online and be harvesting your crop in less than two months from today.
Fastest Flowering Autoflower Strains
Sour Crack Auto
THE FASTEST autoflowering strain that Mephisto Genetics has ever grown, Sour Crack Auto finishes in only seven weeks from seed germination. Sour Crack Auto is bred from Green Crack Auto and 24 Carat genetics. It’s a great strain for commercial quality Sea Of Green autoflower grows. These short plants stay 20 to 28 inches tall, forming rock-hard, resinous buds in quick time. You can expect frosty, high-potency nuggets testing near 20% THC.
| Grow Time | 7 weeks |
|---|---|
| Brand | Mephisto Genetics |
| Pack Size | 1/3/7/18 seeds |
| Yield | 30–60 g/plant |
Buy Sour Crack Auto Seeds🌱
+ Speed Auto
+ Speed Auto by Sweet Seeds are among the quickest finishing autoflower seeds to grow, ready to harvest at just seven weeks from germination. This strain consists of the breeder’s own Critical Mass and Speed Devil #2 Auto genetics, developed through intensive selection for the genetic traits responsible for rapid maturity as well as yield and aromatic qualities. + Speed Auto performs well both indoors and outdoors. The plants grow 20 to 35 inches in height, producing thick, resin-soaked buds with sweet, fruity, and cheesy fragrances. Its effects balance between body stone and head high. 15–20% THC.
| Grow Time | 7 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5/10 seeds |
| Yield | 350–500 g/m2 |
Buy + Speed Auto Seeds🌱
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, taking only seven to eight weeks from seed to harvest. It’s an easy strain to grow with very productive yields. The plants grow vigorously with multiple branches and many bud sites, staying around 20 to 35 inches in height. Fast Bud #2 Auto marijuana has a sweet aroma, exotic taste, strong head high, and powerful body stone. 15–20% THC.
| Grow Time | 7½ weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5/10 seeds |
| Yield | 450–500 g/m2 |
Buy Fast Bud #2 Auto Seeds🌱
Sweet Skunk Auto
Sweet Skunk Auto is one of Sweet Seeds’ best-yielding and most resinous autoflowering varieties—an ideal indoor strain. Super Skunk Auto combines Early Skunk and Critical Mass Auto genetics, backcrossed twice to Early Skunk. The resulting plants grow at lightning speed, finishing at just 7½ weeks from germination, reaching 24 to 35 inches tall. Its buds are dense and covered in trichomes. As the name suggests, Sweet Skunk Auto marijuana has intense skunk aromas with a very sweet background. The buzz is physically relaxing with an uplifting head high. 16–20% THC.
| Grow Time | 7½ weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5/10 seeds |
| Yield | 400–500 g/m2 |
Buy Sweet Skunk Auto Seeds🌱
Alaskan Purple Auto
Alaskan Purple Auto by Seedsman, one of the best seed banks, is a 90% indica cannabis strain that produces good yields in a short time. It finishes growing at eight weeks from seed, with some phenotypes ready to harvest at week seven. They are easy-growing, sizable plants for an autoflowering strain that mature one week later when grown outdoors. The end product has sweet flavors akin to ripe fruit. Alaskan Purple Auto delivers relaxing indica effects. 15–20% THC.
| Grow Time | 7–8 weeks |
|---|---|
| Brand | Seedsman |
| Pack Size | 1–100 seeds |
| Yield | 400–550 g/m2 |
Buy Alaskan Purple Auto Seeds🌱
Red Strawberry Banana Auto
Red Strawberry Banana Auto is an indica-dominant autoflowering strain that displays red and purple-hued flowers in approximately 75% of phenotypes. This fast-finishing variety was created by crossing an elite Strawberry Banana clone to Sweet Seeds’ Red Poison Auto. The plants follow a typical indica growth pattern, becoming 20 to 43 inches in height at maturity, which comes in just seven to eight weeks from germination. The harvest is heavy, with dense buds loaded in trichomes. Its abundance of resin makes this strain well-suited for bubble hash and rosin production, among other processes. Red Strawberry Banana Auto has sweet, candy-like terpenes. The high is serene yet invigorating. 15–20% THC.
| Grow Time | 7–8 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5 seeds |
| Yield | 400–550 g/m2 |
Buy Red Strawberry Banana Auto Seeds🌱
Sweet Gelato Auto
Sweet Gelato Auto by Sweet Seeds is an autoflowering version of one of the most prestigious cookies strains from the Bay Area—Gelato (Sunset Sherbet x Girl Scout Cookies “Thin Mint”)—crossed to Killer Kush Auto. The resulting sativa-dominant plants offer generous yields of potent cannabis in merely eight weeks from germination. Its buds are compact with large trichomes. The scent is earthy, sweet, and fruity with hints of mint and citrus. 18–23% THC.
| Grow Time | 8 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5 seeds |
| Yield | 375–500 g/m2 |
Buy Sweet Gelato Auto Seeds🌱
Honey Peach CBD Auto
Honey Peach CBD Auto is a fifth-generation high-CBD strain of medical cannabis that flowers automatically. Sweet Seeds has taken their best autoflowering strains and combined them with a photoperiod clone featuring high levels of CBD. The result is a fast-flowering indica-type plant that produces THC:CBD ratios between 1:1 and 1:1.5. Honey Peach CBD Auto seeds become short plants ranging from 24 to 39 inches with strong central stems and many side branches. Harvest arrives quickly, in a scant eight weeks after sprouting. These resinous buds smell and taste like peaches with hints of lemon and cypress. The high is mild and therapeutic. 6–9% THC, 7–12% CBD.
| Grow Time | 8 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5 seeds |
| Yield | 400–550 g/m2 |
Buy Honey Peach CBD Auto Seeds🌱
Runtz XL Auto
Runtz XL Auto is the product of crossing the renowned exotic weed strain Runtz to Sweet Seeds’ very best Sweet Gelato Auto phenotypes. It features high terpene concentrations, which gives the buds their intensely fruity aromas and flavors. Runtz XL Auto seeds grow into extra-large autoflowering plants, getting to heights between 24 and 47 inches. They deliver bountiful crops in only eight weeks from sprouting. Runtz XL Auto cannabis has a strong yet balanced effect with peaceful vibes and mental stimulation. 17–25% THC.
| Grow Time | 8 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5 seeds |
| Yield | 400–550 g/m2 |
Buy Runtz XL Auto Seeds🌱
Purple Punch Auto
Purple Punch Auto is a fast, productive, and flavorful autoflowering variety sold by Barney’s Farm Seeds. A top performer indoors and out, this low-maintenance, indica-dominant purple weed strain shows impressive resistance to mold, mildew, mites, and cold weather. The plants max out at 31 inches tall over their short life cycle that takes between 50 and 60 days from seed. Its colorful, dense buds are rich in resin and terpenes, exuding scents of sweet apple pie and cloves. The high is euphoric and de-stressing. 18% THC.
| Grow Time | 50–60 days |
|---|---|
| Brand | Barney’s Farm |
| Pack Size | 1/3/5/10 seeds |
| Yield | 350–400 g/m2 |
Buy Purple Punch Auto Seeds🌱
Fastest Flowering Photoperiod Strains
Green Poison F1 Fast
Green Poison F1 Fast Version is one of the fastest photoperiod marijuana strains on the market, taking just six weeks of flowering to mature. This speedy hybrid was bred by crossing Sweet Seeds’ award-winning Green Poison to its own third-generation autoflowering variant. Intensive selection has ensured that the plants exhibit photoperiod traits while growing vigorously and yielding remarkable indoors and out. Green Poison F1 Fast has a broad cultivability due to its resistance to cannabis mold and rapid bloom phase, harvestable outdoors as early as the end of August. The buds are chunky with incense-like terpene profiles. Its high is happy and unwinding. 15–20% THC.
| Flowering Time | 6 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5/10 seeds |
| Yield | 500–600 g/m2 |
Buy Green Poison F1 Fast Seeds🌱
Passion #1
Passion #1, aka Amstel Gold, is a resilient and robust cannabis variety developed in California during the seventies and made its way to Holland in the eighties, selectively bred ever since. This indica is not only stable, but also effortless to cultivate outdoors, even for beginners. The plants can grow to epic proportions, up to twelve feet tall, while maturing early with harvest falling in September. When grown indoors, the bloom time is incredibly fast at just six weeks. Its flowers are long and full of sugary crystals throughout the leaves and buds. The fragrance is like sour citrus. Passion #1 marijuana delivers both head and body effects. For sale as regular seeds and feminized. 19% THC.
| Flowering Time | 6 weeks |
|---|---|
| Brand | Dutch Passion |
| Pack Size | 1/3/5/10 seeds |
| Yield | 250–750 g/plant |
Buy Passion #1 Seeds🌱
VIEW REGULAR ► VIEW FEMINIZED ►
White Widow Fast
White Widow Fast is a faster flowering version of the world-famous White Widow marijuana strain. It retains the much-loved qualities of the original yet manages to shorten its bloom phase by a week. White Widow Fast’s South Indian and Brazilian Sativa genetics merge to produce super frosty cannabis, so white it appears dipped in sugar crystals. The plants finish fast at six to seven weeks of flowering, yielding decent quantities of knock-out buds with fast-acting, hard-hitting effects. Outdoors, harvest takes place in September. Suitable for cultivation practically anywhere, White Widow Fast is among the best-selling feminized seeds sold online. 15–20% THC.
| Flowering Time | 6–7 weeks |
|---|---|
| Brand | Seedsman |
| Pack Size | 1–100 seeds |
| Yield | 350–450 g/m2 |
Buy White Widow Fast Seeds🌱
Tropicanna Poison F1 Fast
Tropicanna Poison F1 Fast Version is an exceptional strain of cannabis with red buds and ultra-fast flowering. Descending from Tropicanna Cookies (GSC x Tangie), this photoperiod variety adds Sweet Seeds’ special red flower phenotype and the highly regarded Red Poison Auto into the mix. These productive indica-dominant plants finish flowering in just six to seven weeks indoors. Outdoors, the crop matures from late August to early September. Approximately 80% of the plants develop red colors. Its buds have high terpene levels, a lot of resin, and diverse scent and flavor profiles. The buzz affects the mind and body. 16–24% THC.
| Flowering Time | 6–7 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5 seeds |
| Yield | 450–600 g/m2 |
Buy Tropicanna Poison F1 Fast Seeds🌱
C99 x Blueberry Fast
C99 x Blueberry Fast is a rapid flowering hybrid marijuana strain that’s ready to harvest in just 45 days from the start of bloom cycle. The famed Cinderella 99 was crossed to Blueberry and then bred with Seedsman’s Fast parent, resulting in sativa-dominant plants that finish quickly. Its Thai genetics promote large growth patterns in C99 x Blueberry Fast, so expect some stretching. Outdoors, harvest comes in September. You can look forward to high yields of potent marijuana with good bud-to-leaf ratios, making for simple trimming. Its terpene profile is similar to Southeast Asian sativas. Cheap weed seeds for sale in bulk. 15–20% THC.
| Flowering Time | 6–7 weeks |
|---|---|
| Brand | Seedsman |
| Pack Size | 1–100 seeds |
| Yield | 350–450 g/m2 |
Buy C99 x Blueberry Fast Seeds🌱
Crystal Candy F1 Fast
Crystal Candy F1 Fast Version is a quicker flowering take on one of Sweet Seeds’ tastiest varieties, Crystal Candy, which was awarded first-place Best Indica at the Spannabis Champions Cup 2017. It only takes six or seven weeks of blooming to produce big buds with large, aromatic resin glands. Crystal Candy F1 Fast Version grows well indoors and out. Its speedy growth permits a wide range of cultivability, finishing outdoors around the end of August or the beginning of September. The matured buds exude an exquisitely sweet aroma reminiscent of strawberry chewing gum. The high is deeply sedating. 15–21% THC.
| Flowering Time | 6–7 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5 seeds |
| Yield | 450–600 g/m2 |
Buy Crystal Candy F1 Fast Seeds🌱
Jack Herer Fast
Jack Herer Fast is Seedsman’s faster flowering version of Jack Herer, one of the best sativa strains and champion of multiple cannabis competitions since the mid-nineties. This new variety produces enticingly aromatic buds that get greasy with resin in a quick six or seven weeks of flowering. Jack Herer Fast adapts well to indoor, greenhouse, and outdoor cultivation, becoming 31 to 47-inch plants. An early finisher under the sun, harvest comes early during September. The buds retain the creamy, peppery qualities and high potency of the original Jack Herer strain. 15–20% THC.
| Flowering Time | 6–7 weeks |
|---|---|
| Brand | Seedsman |
| Pack Size | 1–100 seeds |
| Yield | 400 g/m2 |
Buy Jack Herer Fast Seeds🌱
Killer Kush F1 Fast
Killer Kush F1 Fast Version is a cross of Sweet Seeds’ third-generation autoflowering strain and an elite OG Kush clone. The OG’s potency remains while flowering time is reduced. These photoperiod plants yield heavy harvests of potent marijuana after a short bloom cycle of seven weeks. Outdoor crops mature by early September. This Kush strain has terrific resin production and delivers a super stoney, body-focused high. The buds have sour and acid aromas in line with the Chemdawg-Diesel family of cannabis. 18–25% THC.
| Flowering Time | 7 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5/10 seeds |
| Yield | 400–600 g/m2 |
Buy Killer Kush F1 Fast Seeds🌱
Pineapple Express #2
Pineapple Express #2 is a faster flowering and more productive version of G13 Labs’ Pineapple Express. A hardy and high yielding strain, Pineapple Express #2 is suitable for cultivation virtually anywhere. The plants are perfect for hostile climates since they resist fungal infections and mature on the double. After a brief seven weeks of flowering, the indoor crop is finished. Outdoors, the plants can grow above eight feet tall, with potential figures over two pounds per plant, ready by the end of September. The flowers are big, bulky, and coated with resin, weighing out heavy on weed scales. The terpenes bring to mind lemon, pine, and spices. Its high is cerebral with a relaxing end. 17–22% THC.
| Flowering Time | 7 weeks |
|---|---|
| Brand | G13 Labs |
| Pack Size | 5 seeds |
| Yield | 700 g/m2 |
Buy Pineapple Express #2 Seeds🌱
Gorilla Girl F1 Fast
Gorilla Girl F1 Fast Version is an extra-fast take on Gorilla Girl, a cross of two celebrated American strains—Gorilla Glue and Girl Scout Cookies. With THC levels up to 31%, Gorilla Girl F1 Fast Version is considered the strongest cannabis strain in the Sweet Seeds catalog. It boasts extreme potency and heavy production while reducing the flowering time to a short seven weeks. These sativa-dominant plants 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. The high is psychoactive and stimulating.
| Flowering Time | 7 weeks |
|---|---|
| Brand | Sweet Seeds |
| Pack Size | 3/5 seeds |
| Yield | 400–550 g/m2 |
Buy Gorilla Girl F1 Fast Seeds🌱
Read Next: 24 Best Landrace Cannabis Strains to Grow from Seed
Disclaimer: Know your laws. Read federal and local/county laws before buying seeds online. We do not promote or undertake in illegal activities.
Consider Bubba’s gift from Humboldt seeds. 6 weeks flowering and nice purple hues
Im growing Bubbas Gift this season and it hasnt started to show sex yet. Just hope its done before the 1st week of October. Weather in the North East US can get really crappy in Oct . Anybody else out there have experience with this strain?
Speedy Chile fast by royal Queen is the fastest I’ve heard of. It’s finished in 56 days from germination and only needs 14 days veg. 16% Thc. Fem photo 80-100cm tall and 500+ grams per m2 indoor. Critical poison fast should be on the list too. Finished in 40-45 days 18% thc Fem photo 500+ grams per m2 indoor.
HI bro, how many plants per m2 can u grow with these??
Wow. This is a real treat for both the consumers and the farmers. Personally, I like Green-O-Matic Auto. It sorts of suits me. Thanks a lot for sharing.
Pineapple Express #2 from G13 Labs all day on my 3rd run with this strain and I have more chasing it
Bro, i have a special pheno of her, been runnin her for like 4 years now.. Its amazing what she does in just 50 days… I like to run an extra 10 days though…
got some free seeds from just cannabis seeds and so I thought I would throw a few of them in the dirt, only one was fem and a hearty little sativa that I topped 3 times for max yield and about 45 days in it looked like I was well on my way to getting 1/2 lb off of her when the buds fattened up in coming weeks considering I had about 4 more weeks before harvest, but just for fun I thought I would check the trichomes at a time I felt was early, and WTF!!! I’m sitting on 15 to 40% amber and no clear trichomes, in 45 days, on a pure sativa!! Well my yield wont be as big but its an early surprise. Wish I would have cloned her,
Just leave a couple small buds and regenerate growth after your harvest.
Lemon Pie Auto takes 3 months/12 weeks seed to buds
Gorilla Girl F1 Fast is my favorite. Not sure if anyone likes it too.
Fast Bud #2 Auto seems one of the exciting options. But I haven’t tried it. Can anyone share how exactly would it be?