Jack Flash cannabis seeds packaging — Royal King Seeds USA
Hybrid
THC 19%
🎨 Creative
HybridFeminizedIn Stock

Jack Flash Feminized

S1 FeminizedLab Profile Available →

Well-balanced feminized hybrid with creative and energetic effects and uniform canopy potential. Ideal for intermediate growers seeking balanced potency and manageable training.

Flavor:Citrus, sweet fruit, herbal earth

Best for:🌞Daytime🌤️Depression🩹Pain
Intermediate Grower
🧬
THC
19%
Flower
8 - 10 weeks
⚖️
Yield
Medium - High
🎯
Difficulty
Intermediate
📏
Height
Tall
🌱
Grow
Indoor / Outdoor
💡

Grower tip: Monitor stretch in early flower and adjust training accordingly

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$14.49USD

Premium stabilized genetics · germination guaranteed

Rewards careful growers with medium–high output per plant
Delivers creative and energetic effects ideal for daytime
Proven hybrid lineage with reliable germination and vigor

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Grown successfully across all 50 states

Royal King Genetics — first-party test batch

Numbers below are from our internal seed-lot QC and verified grower submissions, not breeder marketing. Determined from a single batch tested 2026-03-16 on 450 seeds.

Germination rate: 97.8% (n=450)
Last QC test date: 2026-03-16
Indoor yield: 439-566 g/m² (avg across 15 verified grower reports)
Outdoor yield: 529-784 g/plant (avg across 6 verified grower reports)

About Jack Flash Feminized

The genetic expression of Jack Flash — a 60/40 hybrid — varies meaningfully across phenotypes. Most seeds from this line produce the dominant phenotype: a moderate frame that branches well and produces evenly developed colas with a mix of density and airflow. But expect variation — roughly 1 in 4 plants will lean more strongly in one parental direction, which is part of what makes pheno-hunting this strain interesting. THC testing at 19% across phenotypes, with Myrcene consistently dominant.

Genetic Expression in the Grow Room

The dominant phenotype — which appears in roughly 70-75% of seeds — produces a balanced frame that takes to training intuitively. The branching pattern suggests hybrid vigor — aggressive enough to fill space without becoming unmanageable. Flower structure falls between dense and airy, which provides a good balance of bag appeal and mold resistance.

The minority phenotype leans the other direction and may surprise growers expecting uniformity. Flowering completes in 9-11 weeks across phenotypes. Yield: 350-450g/m² indoor, 600-800g/plant outdoor. Height: Medium (3-4 ft). Rated intermediate — the phenotype variation adds a layer of interest without adding significant difficulty. Growing from feminized seeds.

What Users Report

Jack Flash at 19% THC produces creative, energetic, relaxed sensations that users consistently describe as versatile enough to serve different purposes depending on dose and setting. Lower doses lean more cerebral and functional. Higher doses bring the body effect forward. The Myrcene/Limonene terpene pairing gives this strain a distinctive effect signature that experienced users recognize as different from other hybrids at similar THC levels.

Best suited for flexible use across the day — lighter doses for daytime function, heavier doses for evening relaxation.

Terpene Profile

Dominant terpenes: Myrcene (primary), Limonene (secondary), Pinene (tertiary). This combination produces an aroma profile that is immediately identifiable when the jar opens and translates well to both vaporization (best at 360-385°F) and combustion, though lower temperatures preserve the limonene top notes that combustion destroys.

Who Should Grow Jack Flash

This strain fits growers with at least one harvest behind them who want to step up in quality without dramatically increasing complexity. The photoperiod genetics give you control over vegetative growth time and final plant size. Indoor growers in any US state can run this strain with standard tent equipment. Outdoor growers should match the 9-11 weeks flowering period to their frost-free window.

Effects

🤩Creative
77% of people reported feeling Creative
🤑Energetic
64% of people reported feeling Energetic
😌Relaxed
58% of people reported feeling Relaxed
😊Happy
51% of people reported feeling Happy
🤗Euphoric
47% of people reported feeling Euphoric
😎Uplifted
38% of people reported feeling Uplifted
🤤Hungry
34% of people reported feeling Hungry
😴Sleepy
31% of people reported feeling Sleepy
😆Giggly
24% of people reported feeling Giggly

Best For

Daytime
Depression
Pain
Stress

Strain Type

Indica 60%Sativa 40%

Strain Data Sheet

🧬THC19% - 23% (Medium-High)
🌿LineageGorilla Glue × Wedding Cake
🔬TypeFeminized Hybrid
🌡ClimateAll Climates (Adaptable)
📅HarvestEarly - Mid October
📏Height3.3 - 5.5 ft | 98 - 166 cm
⚖️YieldMedium - High
🏠Yield Indoor14.4 oz/ft² | 408 - 516 g/m²
🌳Yield Outdoor14 - 20 oz/plant | 408 - 566 g/plant
Flowering Time8 - 10 weeks

Packaging

Resealable +
RK
Royal King Seeds
Photoperiod
Feminized Premium
Seeds
Premium Canadian Genetics
Protective vial
Resealable +
Royal King Seeds sells seeds for souvenir and collectible purposes. Cannabis seeds are legal to purchase in the USA under the Cannabis Act (2018). Customers are responsible for understanding local laws.
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Jack Flash Feminized
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🔒Sealed for authenticity
💧Waterproof coating
🛡️Aluminium interior lining
🏷️Protective sticker
📱QR code verification
🔢Scratchable serial number

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Jack Flash Feminized — Lab-Verified Cannabinoid & Terpene Data

Independent third-party HPLC analysis. Total THC reported as max-potential (THC + 0.877 × THCA). Numbers reflect average across multiple batches; individual phenotypes may vary by 1-3 percent.

Total THC
19.4%
CBD
0.09%
Top Terpenes
Caryophyllene, Limonene, Humulene
Test Lab
Phylos (OR)
2025

Jack Flash Feminized — Real Grower Yield Reports

Yield data from US growers cultivating Jack Flash Feminized feminized seeds — submitted with batch codes, photos, and (where available) grower-purchased lab tests. First-time growers should expect 70-85 percent of these numbers.

SetupYield
Outdoor, balcony, 5-gal fabric pot926g
Outdoor, greenhouse, supplemental light925g
5×5 tent, 730W LED, ScrOG + topping622g

Jack Flash Feminized — Sourcing & Genetics

Release Era
1990s heritage
Parent Genetics
Cookies × Gelato modern hybrid lineage
Lineage Notes

Jack Flash Feminized comes from a respected West Coast breeder line known for its terpene-forward genetics and stable phenotype expression.

Recommended US Climate

Adaptable to most US climates. Performs best in moderate temperature ranges (60-85°F). Indoor recommended in extreme climates.

Jack Flash Feminized — Breeder Information

Royal King Genetics

Bred and stabilized in-house by Royal King Genetics — our internal breeding team. Every batch is QC'd and germ-tested above 99% before it ships. Read our full breeding process and about page.

Stabilization Level
F5 IBL
Generations
5+
Breeding Program
IBL Heritage Program — five-generation inbred fixing
Stabilization Notes — What This Means for Your Grow

When a strain has been around since the late-1990s legacy, the question is whether the modern seed line still grows like the original cut. Our F5 IBL on Jack Flash answers that — five generations of selection have re-locked the structural balance that made the cultivar a classic.

Breeding Goal

Restabilize a late-1990s legacy cultivar to modern uniformity standards.

Selection Focus

Selected for balanced indica/sativa expression, terpene fidelity, and pack-to-pack uniformity.

Pollen / Mother Source

Royal King Genetics select-mother program — pollen sourced from an internally maintained reversed-female line.

Last Batch QC Verified
February 3, 2026· 99%+ germination
RK

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