Jack Flash is a hybrid cannabis strain bred by Sensi Seeds from Jack Herer, Super Skunk and a Haze, known for an earthy, piney citrus aroma and an uplifting, cerebral high. Sensi Seeds sells it today as Jack Flash #5 and lists it as a Cannabis Cup winner. Leafly puts it around 17% THC and calls it sativa-dominant, while Sensi’s own listing rates it 65% indica, so plants can lean either way.
Jack Flash Strain at a Glance
| Type | Hybrid; Sensi Seeds lists it as 65% indica, while Leafly calls it sativa-dominant |
|---|---|
| Also known as | Jack Flash #5 |
| Lineage | Jack Herer × Super Skunk × Haze |
| Breeder / origin | Sensi Seeds |
| THC | About 17–20% (typical lab range) |
| CBD | Under 1% |
| Dominant terpenes | Terpinolene, Myrcene, Beta-caryophyllene |
| Aroma and flavor | earthy, skunk, pine, citrus, spicy herbal |
| Reported effects | energetic, focused, uplifted, talkative |
| Best for | daytime use, social settings, creative work |
| Flowering time | 55–75 days |
Where Jack Flash Comes From
Jack Flash is a Sensi Seeds creation that combines the breeder’s own Jack Herer with Super Skunk and a Haze. Sensi’s product page for Jack Flash #5 lists those three ingredients, and Leafly and AllBud describe the same three-way cross. It sits alongside Jack Herer in Sensi’s catalog as one of the Dutch company’s well-known Jack family strains.
Sources differ on its awards. Sensi’s page lists it as a Cannabis Cup winner, AllBud mentions a Dutch High Life Cup win in 1998, and seed retailers mention a third place at the 2004 High Times Cannabis Cup and a 2007 High Life Cup prize. We could not confirm each placing, but it has a long competition record.
The indica and sativa split is also disputed. Sensi lists Jack Flash #5 at 65% indica, AllBud says 60% indica, and Leafly calls it sativa-dominant. Sensi explains that the strain throws two phenotypes, a compact, stocky indica type and a tall, slender sativa type, which helps account for the mixed reports. Leafly lists Django as an offspring.
Jack Flash Effects: What It Feels Like
Leafly reviewers most often describe Jack Flash as energetic, focused and uplifted. Sensi Seeds describes the effect as uplifting, cerebral and happy, with a relaxing side, a mild psychedelic quality and a tendency to make people chatty and thoughtful. AllBud adds a sociable, creative mood with some body relaxation.
In practice it plays like a daytime or early evening strain: a clear, talkative head high carried by a light body feel. The indica-leaning phenotype may feel heavier than the sativa type, so two batches can feel different. Start with a modest amount until you know which kind you have.
Jack Flash Terpenes, Aroma and Flavor
Sensi Seeds describes a strong, earthy aroma with pine and citrus notes that comes through most after a good cure. Leafly lists citrus, spicy herbal and earthy flavors with a skunky undertone, and AllBud adds lemon, sweet and woody notes. Expect a peppery, piney inhale with a citrus lift and a skunky finish.
Leafly reports terpinolene as the dominant terpene, followed by myrcene and caryophyllene. Terpinolene links it to the fresh, herbal Jack Herer profile, while myrcene and caryophyllene add earthy and peppery depth.
- Terpinolene: fruity, piney and herbal, common in classic sativas
- Myrcene: earthy, musky and herbal, also found in mango and hops
- Beta-caryophyllene: peppery and spicy, also found in black pepper and cloves
Terpene levels vary from grower to grower and batch to batch, so check the lab label on the package. Learn more in our guide to cannabis terpenes.
Side Effects and How to Use Jack Flash
Leafly reviewers list dry mouth, dry eyes and headache as the most common complaints. AllBud adds that dizziness is possible but unlikely. Keep water handy and pace your sessions.
How strong Jack Flash feels depends on the batch, your tolerance and how you consume it. Start low, go slow, and read our guide to dosing cannabis.
Do People Use Jack Flash for Medical Reasons?
Leafly readers most often report reaching for Jack Flash during stress (37%), anxiety (30%) and depression (25%). These are personal reports, not clinical evidence.
These are user reports, not clinical findings. For what research actually supports, see our cannabis health and research section, and talk to your doctor before using cannabis for a health condition.
Growing Jack Flash
- Difficulty: Moderate
- Flowering: 55–75 days
- Yield: Heavy; about 600 g per plant outdoors (Sensi Seeds)
- Height: About 100–180 cm indoors; 180–250 cm outdoors
- Environment: Indoor, greenhouse or outdoor in warm, sunny climates
Sensi Seeds sells Jack Flash #5 as feminized seed and says it suits growers with some experience. Expect two phenotypes: a compact indica type around 100 cm indoors that works well in a sea of green, and a taller sativa type that can reach 180 cm indoors and stretches a lot in flower. Sensi reports good results with SCROG, lollipopping and supercropping, a flowering time of 55–75 days and outdoor yields around 600 g per plant. It does best in long, warm summers, so outdoor growers in cooler, damp regions should plan for an early finish or a greenhouse, and keep airflow high late in flower.
Home-grow rules depend on the state: adults can grow at home in states such as California (six plants per residence), Michigan (12 per residence) and Oregon (four per household), while Washington and Illinois allow home growing only for registered medical patients. Check your state in our cannabis laws by state guide before you plant anything.
Strains Like Jack Flash
- Jack Herer: its main parent from the same breeder
- Super Silver Haze: another classic Skunk and Haze sativa blend
- Jack Frost: another Jack Herer descendant
- Amnesia Haze: a Dutch, Haze-heavy daytime strain
- Skunk #1: the Skunk family behind Super Skunk
Browse more hybrid strains, the full strain directory, or our guide to cannabis strains.
More Hybrid Strains to Explore
Jack Frost · Jealousy · Jenny Kush · Inzane Auto · Ice Wreck · I-95 · All hybrid strains
Where to Buy Jack Flash
Dispensary menus change every week, and Jack Flash may be sold under its own name, as a cross or as a pre-roll or vape. The fastest way to find it is to check store menus online before you go. In Vancouver, browse Vancouver dispensaries and check the menus at stores like High End Market Place and Main Street Marijuana North. In Chicago, browse Chicago dispensaries and check the menus at stores like Ivy Hall – Damen and Ivy Hall – Logan Square. You can also browse licensed dispensaries in every state we cover. Adults 21 and older can buy with a valid photo ID; see cannabis laws by state for purchase limits.
Jack Flash FAQ
Is Jack Flash indica or sativa?
It is a hybrid, and sources disagree on which way it leans. Sensi Seeds lists 65% indica, while Leafly calls it sativa-dominant.
Who bred Jack Flash?
Sensi Seeds, the Dutch seed company that also created Jack Herer.
What is Jack Flash a cross of?
Jack Herer, Super Skunk and a Haze variety, per Sensi Seeds.
How strong is Jack Flash?
Moderately strong. Leafly lists about 17% THC and AllBud says up to 20%.
How long does Jack Flash take to flower?
Sensi Seeds gives 55–75 days, depending on the phenotype.
For adults 21+ in legal states. Strain information reflects breeder descriptions, lab data and user reports; effects vary by person and batch. Not medical advice.
