Fast Flowering Cannabis Seeds USA, Quick Harvest Strains

Fast flowering cannabis seeds combine photoperiod genetics with accelerated flowering times, typically finishing 1-2 weeks earlier than standard strains. Ideal for outdoor growers in northern US states who need to harvest before frost, and indoor growers who want faster turnaround between cycles. These strains maintain the potency and yield of standard photoperiod genetics while shaving critical weeks off the flowering timeline.

All strains in this collection are bred & stabilized in-house by Royal King Genetics

209 strains available

Flowering Time6-8 Weeks

Time Saved1-2 Weeks Faster

YieldStandard to High

Best ForShort Seasons & Speed

Fast Flowering Seeds catalog at a glance

Our fast flowering seeds collection currently holds 209 strains in active inventory with verified THC content ranging from 5% at the low end to 30% at the high end (median 20%). Average flowering time across the catalog is 9 weeks from 12/12 flip for photoperiod genetics or seed-to-harvest for autoflowers.

Strains

209

THC range

5-30%

Median THC

20%

Avg flower

9wk

Autoflowering: 209 strains (100% of the catalog), finishes 8-10 weeks seed-to-harvest, no photoperiod switch.
Indica-dominant: 209 strains, body-led effects, compact structure, Myrcene-Caryophyllene terpene signature typical.
Alphabetical lineup starts with: 3X Crazy, 5th Element, 9 Pound Hammer, see the full grid below for filters, lab data and grower reports.

What Are Fast Flowering Cannabis Seeds?

Fast flowering seeds are photoperiod strains bred to complete their flowering cycle faster than standard versions. They achieve this through selective breeding with fast-finishing genetics or by incorporating a small percentage of ruderalis genes without making them fully autoflowering. The result is a plant that still requires a 12/12 light cycle to flower but finishes 7-14 days sooner than the original strain, a critical advantage for outdoor growers in regions with early fall frost.

Best Fast Flowering Strains

Our fast-flowering collection includes Quick One (8 weeks total from seed), Fast Buds Critical (6 weeks flower), Speed Haze (8 weeks flower instead of 12), and Fast Gorilla Glue (7 weeks flower). These strains deliver comparable potency and yield to their standard counterparts while finishing significantly faster. Indoor growers can fit an extra harvest cycle per year with fast-flowering genetics.

How to Choose Fast Flowering Seeds

Consider whether you need a full photoperiod plant (with veg control) that flowers quickly, or if a standard autoflower would serve your needs. Fast-flowering photoperiod strains give you the advantage of controlling plant size during veg while still getting a faster harvest. Compare flowering times between fast and standard versions of the same strain. For outdoor growers, calculate whether the fast version will finish before your local first frost date.

Cannabinoid & Terpene Reference Data

Fast-flowering genetics complete flowering in 6-8 weeks instead of the 9-11 weeks typical of standard photoperiod strains. Lab data shows that fast-flowering strains achieve 90-95 percent of the potency of their standard counterparts despite the shorter flower window, modern breeding has effectively closed the speed-vs-potency gap.

Strain	Total THC	CBD	Top Terpenes
Northern Lights	21.1%	0.10%	Myrcene, Pinene, Limonene
Bubba Kush	22.8%	0.10%	Caryophyllene, Limonene, Myrcene
Critical	21.4%	0.13%	Myrcene, Pinene, Caryophyllene
Hindu Kush	20.5%	0.12%	Myrcene, Humulene, Pinene
Quick One	14.8%	0.10%	Myrcene, Pinene, Limonene
Speed Haze	19.7%	0.06%	Pinene, Caryophyllene, Limonene
Power Plant	23.1%	0.06%	Myrcene, Caryophyllene, Pinene
Master Kush	21.4%	0.08%	Myrcene, Pinene, Caryophyllene
Top 44	17.9%	0.11%	Myrcene, Pinene, Caryophyllene
Sleestack	19.2%	0.08%	Myrcene, Caryophyllene, Pinene

Tests use HPLC analysis. Fast-flowering strains tested at week 7-8 of flower (vs week 9-10 for standard versions). The 1-2 week time savings is critical for outdoor growers in regions with first-frost dates in late September or early October.

Aggregated Grower Yield Reports

Fast-flowering harvest reports, many submitted by growers in cold-climate northern states (Maine, Minnesota, Wisconsin, Michigan, Vermont) where standard photoperiod strains often fail to finish before fall frost destroys the crop.

Strain	Yield (g/plant)	Setup	Reported THC	Flower Weeks
Northern Lights	360g	3×3 tent, 400W LED, LST	20.9%	8w
Bubba Kush	425g	4×4 tent, 600W LED, LST	22.6%	8w
Critical	545g	4×4 tent, 600W LED, top + main-line	21.0%	7w
Hindu Kush	580g	Outdoor, in-ground, full sun	20.0%	8w
Quick One	110g	Outdoor, 5-gal fabric pot, full sun	14.6%	7w
Speed Haze	510g	5×5 tent, 730W LED, ScrOG	19.4%	8w
Power Plant	720g	Outdoor, raised bed, full sun	22.8%	8w
Master Kush	380g	4×4 tent, 600W LED, LST	21.0%	8w
Top 44	245g	3×3 tent, 400W LED, single-cola	17.6%	7w
Sleestack	420g	Outdoor, 15-gal fabric pot, full sun	18.8%	7w

Frequently Asked Questions

How fast do fast flowering seeds finish?

Fast flowering strains typically finish flowering in 6-8 weeks compared to 8-11 weeks for standard versions. This 1-2 week advantage can be critical for outdoor growers who need to harvest before frost arrives.

Are fast flowering seeds the same as autoflowers?

No. Fast flowering seeds are photoperiod plants that require a 12/12 light cycle to flower, they just do it faster. Autoflowers flower regardless of light cycle. Fast flowering seeds give you veg control that autoflowers do not offer.

Do fast flowering strains yield less?

Modern fast flowering strains produce yields comparable to their standard counterparts. The breeding focus has been on maintaining yield and potency while reducing flowering time. Some may yield 5-10% less than the original, but the time savings often outweigh this.

Who should use fast flowering seeds?

Fast flowering seeds are ideal for outdoor growers in northern states with short seasons, indoor growers wanting more harvest cycles per year, and anyone who needs a quick turnaround without switching to autoflowers.

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